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The effect of different methods of remuneration on the behaviour of primary care dentists

  1. Paul Brocklehurst1,*,
  2. Juliet Price2,
  3. Anne-Marie Glenny3,
  4. Martin Tickle1,
  5. Stephen Birch4,
  6. Elizabeth Mertz5,
  7. Jostein Grytten6

Editorial Group: Cochrane Effective Practice and Organisation of Care Group

Published Online: 6 NOV 2013

Assessed as up-to-date: 25 AUG 2013

DOI: 10.1002/14651858.CD009853.pub2


How to Cite

Brocklehurst P, Price J, Glenny AM, Tickle M, Birch S, Mertz E, Grytten J. The effect of different methods of remuneration on the behaviour of primary care dentists. Cochrane Database of Systematic Reviews 2013, Issue 11. Art. No.: CD009853. DOI: 10.1002/14651858.CD009853.pub2.

Author Information

  1. 1

    School of Dentistry, The University of Manchester, Manchester, UK

  2. 2

    The University of Manchester, School of Dentistry, Manchester, UK

  3. 3

    School of Dentistry, The University of Manchester, Cochrane Oral Health Group, Manchester, UK

  4. 4

    Faculty of Health Sciences, McMaster University, Centre for Health Economics and Policy Analysis, Department of Clinical Epidemiology and Biostatistics, Hamilton, Ontario, Canada

  5. 5

    San Francisco School of Dentistry, University of California, Preventative and Restorative Dental Sciences, Suite 410, San Francisco, USA

  6. 6

    University of Oslo, Department of Community Dentistry, Oslo, Norway

*Paul Brocklehurst, School of Dentistry, The University of Manchester, Coupland III Building, Oxford Road, Manchester, M13 9PL, UK. paul.brocklehurst@manchester.ac.uk. paul.r.brocklehurst@btopenworld.com.

Publication History

  1. Publication Status: New
  2. Published Online: 6 NOV 2013

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Summary of findings    [Explanations]

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

 
Summary of findings for the main comparison. Fee-for-service remuneration for encouraging fissure sealant placement for second permanent molars in 12- to 14-year-olds

Population: Dentists seeing children with erupted second permanent molars
Settings: Scotland, in areas representing the four most deprived categories (out of seven) in the Scottish post code based system defining deprivation
Intervention: Fee-for-service remuneration

Control: No specific intervention

OutcomesIllustrative comparative risks (95% CI)Relative effect
(95% CI)
No. of Participants
(studies)
Quality of the evidence
(GRADE)

Assumed riskCorresponding risk

ControlFee-for-service remuneration

Measures of clinical activity: mean percentage of 12- to 14-year-olds receiving fissure sealants for second permanent molars per dentist (weighted by number of children seen) - adjusted1
Follow-up: 18 months
-RD 9.8% higher (1.8% higher to 17.8% higher)3-133 dentists
(1 study)
⊕⊝⊝⊝
very low4

Measures of clinical activity: mean percentage of 12- to 14-year-olds receiving fissure sealants for second permanent molars per dentist (weighted by number of children seen) - unadjusted2
Follow-up: 18 months
26.3% (CI NR)RD 7.1% higher (1.9% lower to 16.1% higher)RR 0.27 (CI NR)133 dentists
(1 study)
⊕⊝⊝⊝

very low4

Healthcare costs: cost-effectiveness of fee-for-service vs. control (reported as the "% change in outcome per £[GBP]" - currency year NR)5
Follow-up: 18 months
-- 0.10 (CI NR)68 dentists
(1 study)
⊕⊝⊝⊝

very low4

CI: Confidence interval; GBP: Pound Sterling; NR: Not reported; RD: Risk difference; RR: Risk ratio

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

 1The model adjusted for the baseline dental practice-level covariates (deprivation category for the area of dental practice, number of partners in practice, throughput of 11- to 13-year-olds and the number of restorative fissure sealants placed on first permanent molars at baseline).
2The basis for the assumed risk is the risk in the control group (i.e. the probability of a dentist in the control group fissure sealing a second permanent molar of a 12- to 14-year-old). The corresponding risk (the risk difference) is based on the assumed risk in the control group and the relative effect of the fee-for-service remuneration (the risk ratio).
3Statistically significant at the 5% level.
4 Quality of the evidence
  • Risk of bias: high
  • Inconsistency: undetected (single study)
  • Indirectness: yes

    • The dentists only received the fee-for-service remuneration in the first six months of the study but the data were collected 18 months after the start of the trial. The effects of the fee-for-service remuneration would have been attenuated if 18-month data were analysed
    • The fee-for-service remuneration did not affect National Health Service capitation payments which were GBP 2.76 per month to age 12 and GBP 4.01 thereafter, so it is not possible to show the effect of fee-for-service remuneration compared to capitation (only fee-for-service and capitation compared to capitation)
    • The authors suggested that the dentists may have found it too inconvenient to claim a fee from the research team, rather than via the routine National Health Service channel, which would normally be the route for claiming fee-for-service remuneration
    • The average age at baseline was from 13.2 years in the education arm to 13.3 years in the both fee-for-service and education arm, and the data on fissure sealant placement was collected up to 18 months after this baseline so some of the children may have already started to experience decay if their second permanent molars erupted at around 12 years old. Attempting to place fissure sealants soon after the eruption of second permanent molars is considered preferable to waiting a fairly long time after eruption, so the percentage of children with fissure sealants at the end of the study may have been attenuated (this could apply across all of the study arms). Records of any caries already present or any restorations placed would be useful as this could impact on the proportion of fissure sealants placed i.e. dentists in the study may have placed restorations instead of sealant. The authors noted that only two-thirds of eligible dentists claimed a fee, perhaps due to the fact that the child already had caries in their second permanent molars
    • The dentists were working in deprived areas of Scotland, which would have different levels of need compared to Scotland as a whole
    • The economic evaluation does not take into account the payments from the state (i.e. the fee-for-service remuneration in one arm and the capitation payments in both arms, which would be difficult to include as they are paid for dental care as a whole) so the only costs taken into account are the costs to the dental practices (in terms of staff time and consumables) and the costs to parents. An alternative perspective would be to investigate the cost-effectiveness from the point of view of the state which pays the fee-for-service (in place of the dental practices) and parents

  • Imprecision: potentially - the total sample size is lower than the required sample size calculated by the authors
  • Publication bias: undetected (single study)
  • Large effect: not relevant (applies to studies with no threats to validity)
  • Plausible confounding would change the effect: not relevant (applies to studies with no threats to validity)
  • Dose response gradient: not relevant (applies to studies with no threats to validity)

5Outcome in the incremental cost-effectiveness ratio (ICER) is not specified and can only be assumed to relate to sealant placement

 Summary of findings 2 Capitation remuneration compared to fee-for-service remuneration for encouraging routine continuing dental care of children

 

Background

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

In medicine, methods of remuneration that form the provider payment have been linked with the clinical and professional behaviour of primary care physicians (Donaldson 1989).

In a Cochrane Effective Practice and Organisation of Care (EPOC) Group review of the effects of the method of remuneration on the behaviour of primary care physicians, fee-for-service payments were associated with an increase in the quantity of primary care services, but changes to patient outcomes were equivocal (Gosden 2000).

A more recent EPOC Group review examined the effect of financial incentives on the quality of health care provided by primary care physicians (Scott 2011). Again, there was insufficient evidence to determine the impact of financial incentives on the quality of primary health care. Six of the seven included studies demonstrated positive but modest effects on a minority of the measures of quality of care, and the remaining study found no effect. Most of the studies had a substantial risk of bias due to factors such as selection bias (due to non-randomisation and, in randomised studies, due to analysis at the level of the medical group combined with lack of reporting on changes in the composition of these medical groups between baseline and follow-up, or between the intervention and control groups).

An EPOC Group overview of reviews was carried out to evaluate the effects of financial incentives on the behaviour of healthcare professionals and patient outcomes (Flodgren 2011). This overview included four reviews, two of which were judged to be of moderate quality and the remaining two were judged to be of high quality. The 32 studies that these four reviews reported on were found to be of low to moderate quality. Fee-for-service and capitation payments were generally effective (improving 7/10 outcomes and 48/69 outcomes, respectively), while fixed salary payments were generally ineffective (improving 3/11 outcomes). The review also considered payments for providing a prespecified level of activity or providing a change in activity or quality of care, and found that this was generally effective (improving 17/20 outcomes). In addition, the review considered the effect of financial incentives in general across categories of outcomes and found that they were generally effective at improving processes of care, referrals and admissions, and prescribing costs. However, financial incentives were ineffective in improving compliance with guidelines' outcomes, and had mixed effectiveness on consultation rates. No evidence was found for the effect of financial incentives on patient outcomes. Vote counting was used to summarise the direction of the effect, rather than a meta-analysis. Many studies utilised a controlled before-after design, and adjusting for these reduced the overall impact on effectiveness. There were also concerns about the completeness and generalisability of the evidence.

 

Description of the condition

This review considered all aspects of dental care undertaken by primary care dentists (defined as clinicians that deliver routine or mainstream dental care in a primary care environment), excluding the provision of specialist services or the management of adult or child patients with special needs.

 

Description of the intervention

The main mechanisms for remunerating primary care dentists include fee-for-service, fixed salary and capitation payments (Grytten 2005) i.e. service throughput-based (fee-for-service), time-based (fixed salary) and patient-based (capitation). These vary considerably across different countries and are heavily influenced by the prevailing political and professional culture (Grytten 2005). Capitation payments tend to secure effectiveness at the cost of patient selection and under treatment, while fee-for-service payments secure quality but often suffer from cost containment problems (Gosden 2000; Grytten 2005). For example, Birch 1988 found that where primary care dentists have a substantial influence over demand for care, there are strong incentives to over treat. Chalkley 2006 also found that treatment for patients exempt from payment was more intensive when provided by self employed primary care dentists compared to their salaried counterparts. In a natural experiment where public dental officers in one county were given the opportunity to renegotiate their contract from a fixed salary contract to a combined capitation and fixed salary contract, “the transition to an incentive-based remuneration system led to an increase in the number of individuals under supervision, without either a fall in quality or a patient selection effect” (Grytten 2009). Salary remuneration removes the link between income and the level and type of services delivered, or patients served, leading to high costs per patient (Grytten 2005). A recent review of the impact of introducing a new National Health Service contract on the behaviour of primary care dentists in the United Kingdom found that clinicians were very sensitive to changes to remuneration (SDO 2011). This reduced job satisfaction and morale (Harris 2009), adversely affected patient access and changed the service and mix of activity, or led to a shift of primary care dentists from a national contract to the private sector (Steele 2009).

 

How the intervention might work

Financial incentives within health care remuneration systems have the potential to align the provision of health services with the aims of the health system, e.g. making the services more effective, more equitable or more patient-centred. Financial incentives involve transferring money from ‘buyers’ (patients or third-party payers such as governments or insurers) to ‘sellers’ (individuals or groups of clinicians, or their employers) on the condition that the sellers behave in a certain way, e.g. by providing a particular health service, sometimes at a specified level of quality (Scott 2011).

The economic theory explains that if the size of the payment is greater than the marginal (i.e. additional) costs of the behaviour change, then the cost-benefit ratio of the behaviour change can be lowered and this can make the behaviour change more likely to happen (Scott 2011). There may be heterogeneity in the marginal costs of changing behaviour among the providers, e.g. due to differences in administrative costs of practices of different sizes, as larger practices may have lower unit costs (Scott 2011). The theory highlights that, in addition to the method of remuneration, other factors such as the level of payment (particularly in terms of the proportion of total revenue from the remuneration system) are likely to have an impact, due to the economic concepts of substitution and income effects. How payments are utilised by a practice is also significant, particularly regarding how the payments are distributed between groups of providers and whether any of the payments are invested into service provision to reduce the marginal costs (which reduces the cost-benefit ratio), rather than being used to pay the providers (Scott 2011). The relative impact of other sources of motivation (such as professional autonomy) has a bearing on the effect of financial incentives, and these may vary for different providers and in different settings (Scott 2010; Scott 2011) . It is important to note that financial incentives may also influence the quality and cost of health service provision by influencing recruitment and retention and thereby influencing the mix of providers. If poorly designed, financial incentives can have unintended effects such as incentivising providers to prioritise one disease area at the expense of other disease areas, such that the overall net impact on health service provision is detrimental.

Primary care dentists operate their practices as businesses (Grytten 2005; Tickle 2011) so they differ from many other healthcare professionals in that they take all the financial risk for service provision, receiving little or no support to cover initial start-up costs or for the development of their capital infrastructure. As a result, they are potentially more sensitive to financial incentives within the remuneration system, which represents their principal source of income; changes in the clinical activity of primary care dentists in the United Kingdom have been documented following the introduction of new methods of payment in the National Health Service (McDonald 2012; Tickle 2011). In addition, unlike primary care physicians, whose predominant function is the management of symptomatic patients or those with chronic conditions, the bulk of service delivery in dentistry in most industrialised countries, in terms of volume of activity, is based on the regular attendance of asymptomatic patients. This can produce distortions in both the demand and supply side of provision (Wright 2001). Demand can be influenced by health literacy and patient expectations of care (Gregory 2007; Milsom 2009; Steele 2009), while supply can be influenced by the financial incentives inherent within the remuneration system, leading to supplier-induced demand (Birch 1988; Tickle 2011). Despite this, remuneration systems in primary care dentistry have received relatively little attention from a health economics perspective (Grytten 2009).

 

Why it is important to do this review

In dentistry, there is some evidence from observational study designs that methods of remuneration can impact on the behaviour of clinicians in primary care environments (Chalkley 2006; Grytten 2005; Tickle 2011). In medicine, fee-for-service payments are associated with an increase in the quantity of primary care services, but changes to patient outcomes are equivocal (Gosden 2000). As a result, it is important to understand the effects that different remuneration systems have on the pattern of service activity in dentistry and the patient outcomes generated (Grytten 2005). Evidence from experimental designs would also help to determine the most appropriate method of service delivery for the needs of a given population in order to inform future workforce planning (Grytten 2009).

 

Objectives

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

To evaluate the effects of different methods of remuneration on the level and mix of activities provided by primary care dentists and the impact this has on patient outcomes.

 

Methods

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms
 

Criteria for considering studies for this review

 

Types of studies

We included the following study designs that met the Cochrane EPOC Group criteria (EPOC 2013).

  • Randomised controlled trials (RCTs)
  • Non-randomised clinical trials (NRCTs)
  • Controlled before-after (CBA) studies (at least two sites in each group)
  • Interrupted time series (ITS) studies

We reported numerical data on an individual study basis and outcome data for the multiple publications of one trial (Coventry 1989) were reported as one.

 

Types of participants

We examined studies involving primary care dentists providing routine dental care in primary care environments.

 

Types of interventions

We defined the method of remuneration as the payment that directly determines or influences the personal income of the primary care dentist. We included the following remuneration systems.

  • Fee-for-service payments
  • Fixed salary payments
  • Capitation payments
  • Blended payments (combinations of above)

Fee-for-service remuneration was defined as a payment made to a primary care dentist for every item of service or unit of care that they provide. Salaried remuneration was defined as a lump sum payment made to a primary care dentist for a set number of working hours or sessions per week. Capitation remuneration was defined as a payment based on the number and types of patients whose care the provider takes responsibility for.

 

Types of outcome measures

We only reported objective outcome measures and subjective outcome measures that used standardised validated instruments.

 

Primary outcomes

We considered the following as primary outcome measures.

  • Measures of clinical activity
    • Number of activities undertaken in a specified time period including examinations, oral hygiene instruction, scaling and polishing, periodontal treatment, restorations, root canal treatments, extractions and prostheses
    • Number of sessions over which treatment activity is distributed
    • Time taken and session length, or both, for treatment activities
    • Clinician type utilised
  • Measures of health service utilisation
    • Proportion of a population receiving care
    • Re-attendance rates
    • Recall frequency
    • Levels of oral health inequalities by socio-economic status, education or income
    • Proportion of population not receiving care (non-attendance rates)
  • Healthcare costs

  • Patient outcomes
    • Disease reduction, including the number of new carious teeth, the proportion of patients with a basic periodontal examination greater than a score of two, and the proportion of patients with sites that bled on probing
    • Health maintenance, including the proportion of patients that did not require any operative treatment
    • Patient satisfaction, including the proportion satisfied with the dental care they received, the proportion satisfied with the waiting time for an appointment, and the proportion reporting that they felt involved in decisions about their care

 

Secondary outcomes

We considered the following as secondary outcome measures.

  • Measures of non-clinical behaviour of primary care dentists including the rates of performing specified non-clinical behaviours (e.g. education and training), when specified as a secondary outcome.
  • Measures of dental practice profitability/income.
  • Any unintended effects of the remuneration systems, including supplier-induced demand when the service provided is not based on need (Birch 1988), changes to the types of treatment offered, and limitations to access (see Tickle 2011 for a conceptual framework).

 

Search methods for identification of studies

Michelle Fiander, Trials Search Co-ordinator (TSC) for the Cochrane EPOC Group, wrote the search strategies. The TSC searched the Cochrane Database of Systematic Reviews and the Database of Abstracts of Reviews of Effects (DARE) for related systematic reviews, and the databases listed below for primary studies. Searches were conducted in June 2013; exact search dates for each database are included with the search strategies in Appendix 1.

 

Electronic searches

 

Databases

  • Cochrane Central Register of Controlled Trials (CENTRAL), Issue 7, 2013, Wiley
  • MEDLINE, 1946 - June 2013, In-Process and other non-indexed citations, Ovid
  • EMBASE, 1947 - June 2013, Ovid
  • EPOC Group, Specialised Register, June 2013, Reference Manager
  • EconLit, Dissertations & Theses, 1969 - June 2013, ProQuest
  • PAIS International, Political Science,Worldwide Political Science Abstracts, June 2013, Proquest
  • CINAHL (Cumulative Index to Nursing and Allied Health Literature), 1980- June 2013, EbscoHost
  • NHS Economic Evaluation Database (EED), Issue 7, 2013, Wiley
  • Health Economic Evaluations Database (HEED), Issue 7, 2013, Wiley

We used search strategies that were comprised of keywords and, when available, controlled vocabulary such as MeSH (Medical Subject Headings). The TSC finalised search strategies using an iterative development process in which citations identified by various search terms were screened for relevance, either by review authors or the TSC. In this manner, individual terms and combinations of terms were assessed as relevant or irrelevant and were included or omitted from the final search strategies. We did not place any restrictions on either the date or language used. We searched all the databases from their start date forward.

We used two methodological search filters to limit retrieval to appropriate study designs: the Cochrane Highly Sensitive Search Strategy (sensitivity- and precision-maximising version, 2008 revision) to identify randomised trials (Higgins 2011); and an EPOC methodology filter to identify non-RCT designs. We have provided all the search strategies and specific run dates in Appendix 1.

 

Grey literature sources

We scanned publication titles on the following grey literature websites.

We examined websites for grey literature manually without using search interfaces as they do not usually support complex Boolean or other operators. We conducted the latest search in August 2013.

 

Searching other resources

We also undertook the following.

  • Reviewed reference lists of all included studies.
  • Conducted cited reference searches for all included studies in ISI Citation Indexes via Web of Knowledge.
  • Contacted authors of relevant studies/reviews to clarify reported published information and to seek unpublished results/data.
  • Screened the following individual journals from January 2010 to December 2012: Health Economics; Journal of Political Economy; Journal of Health Services Research and Policy; European Journal of Health Economics; and Journal of Applied Economics.

 

Data collection and analysis

We managed the whole review process using Review Manager 5 (RevMan 2012).

 

Selection of studies

After we had identified the titles and abstracts from the electronic searches, we downloaded them to a reference management database and removed the duplicates. Three of the review authors (PRB, JCP and AMG) independently examined the remaining references. We excluded studies that did not meet the inclusion criteria and obtained full-text copies of the references that appeared to meet the inclusion criteria to assess for inclusion. We resolved differences by discussion and recorded the excluded studies in the Characteristics of excluded studies table.

 

Data extraction and management

Three of the review authors (PRB, JCP and AMG) independently extracted data from the included studies and resolved any differences by discussion.

We extracted the following data into the Characteristics of included studies tables.

  • Methods (study type and duration of study)
  • Participants (setting, unit of randomisation, unit of assessment/analysis, method of recruitment, inclusion criteria and exclusion criteria)
  • Interventions (details of interventions and control group)
  • Outcomes (primary and secondary (as specified in the protocol for this review) and adverse outcomes)
  • Source of funding

We extracted the following into the Appendices.

  • Number of participants (number randomised, number analysed and number not analysed with reasons, each by study arm)
  • Baseline characteristics and outcomes

 

Assessment of risk of bias in included studies

Three review authors (PRB, JCP and AMG) independently assessed the risk of bias of the included studies and considered other factors that affect the quality of evidence, including inconsistency, indirectness, imprecision and publication bias. We resolved disagreements by discussion.

We assessed the risk of bias for studies with a control group (RCTs, NRCTs and CBAs) using the following criteria (EPOC 2011; Higgins 2011).

  • Random sequence generation
  • Allocation concealment
  • Blinding of participants and personnel
  • Blinding of outcome assessment
  • Incomplete outcome data
  • Other bias (including baseline characteristics and outcomes, and protection against contamination)

We assessed ITS studies using the following criteria (EPOC 2011).

  • The intervention was independent of other changes
  • The shape of the intervention effect was prespecified
  • The intervention was unlikely to affect data collection
  • Incomplete outcome data were adequately addressed
  • The study was free from selective outcome reporting

We tabulated the description of the domains for each included study, along with a judgement on the risk of bias (low, high or unclear) for each domain, based on the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We planned to undertake a summary assessment of the risk of bias for the primary outcome across the studies (Higgins 2011). For each study, we provided the following summary assessment of the risk of bias.

  • Low risk when there is a low risk of bias across all domains.
  • Unclear risk of bias when there is an unclear risk of bias in one or more of the domains.
  • High risk of bias when there is a high risk of bias in one or more of the domains.

 

Measures of treatment effect

We reported outcomes for each included study in natural units.

For RCTs, NRCTs and CBAs, we reported pre-intervention and post-intervention means or proportions for all data points for both intervention and control groups where baseline results were available. Had data allowed, we had planned to calculate the unadjusted and adjusted (for any baseline imbalance) absolute change from baseline with 95% confidence intervals (CIs). For continuous variables, we reported mean differences (MDs). Dichotomous variables would have been reported as risk ratios (RRs) together with 95% CIs.

Had eligible ITS studies been identified, we would have extracted the difference in slope and the difference in pre- to post-intervention levels. We had planned to analyse the post- versus pre-intervention difference (adjusted for trends) at specific time points (three months, six months and six-monthly thereafter). If the differences were not available in the primary reports, we would have reanalysed the results using data from graphs or tables.

We have presented the findings of the main comparisons from the included studies in the Summary of main results in order to interpret the results and draw conclusions about the effects of different interventions along with the quality of the evidence.

 

Unit of analysis issues

For cluster-RCTs, we undertook analysis at the same level as the randomisation or at the individual level, accounting for the clustering. For cluster-RCTs with unit of analysis error we did not report the P values or 95% CIs, as analyses not accounting for the design effect have the potential to inflate the type 1 error rate and result in artificially narrow CIs (Ukoumunne 1999). The point estimate is not affected by unit of analysis errors.

 

Dealing with missing data

We explicitly stated where studies had missing data.

 

Assessment of heterogeneity

We had planned to assess heterogeneity using The Cochrane Collaboration's test for heterogeneity, where P < 0.1 was to be considered significant (Higgins 2011). However, due to variations in comparisons made, plus methodological heterogeneity, it was felt inappropriate to pool data.

 

Assessment of reporting biases

If more than 10 studies had been identified for meta-analysis, we had planned to assess publication bias according to the recommendations on testing for funnel plot asymmetry (Higgins 2011).

 

Data synthesis

We had planned to undertake meta-analyses for clinically homogeneous RCTs that reported the same outcome measures: RRs for dichotomous data and MDs for continuous data, using random-effects models (or fixed-effect models if fewer than four studies were included). Given the lack of relevant studies, we undertook a qualitative synthesis.

 

Subgroup analysis and investigation of heterogeneity

If data had allowed, we had planned to group the results according to the type of remuneration system. However, we were unable to undertake subgroup analyses due to the lack of eligible studies.

 

Sensitivity analysis

In order to determine the robustness and consistency of the results, we had planned to compare RCTs (when at low risk of bias) to other studies, had we identified sufficient studies.

 

Results

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms
 

Description of studies

Characteristics of the included studies are presented in detail in Appendix 2 and summarised in the Characteristics of included studies tables.

 

Results of the search

We identified 4737 studies from the literature search. Following two rounds of screening, we assessed 13 publications in detail (Figure 1).

 FigureFigure 1. Study flow diagram.

 

Included studies

Two studies (from five publications) met the inclusion criteria (Clarkson 2008; Coventry 1989), with data from 503 dental practices, representing 821 dentists and 4771 patients. Both were RCTs and were undertaken in the United Kingdom.

 

Excluded studies

We excluded eight studies (Blinkhorn 1996; Chalkley 2008; Fiset 2000; Holloway 1997; Mayer 2000; Mellor 1994; Mellor 1997; Rosen 1977); five on the basis that they were uncontrolled before-after studies examining the impact on clinical activity before and after a change to the remuneration system. We excluded one ITS study on the basis of an inadequate number of time points between changes in the remuneration rate offered to primary care dentists. In addition, we excluded a cohort and an observational extension of the included Coventry 1989 study (See Characteristics of excluded studies tables).

 

Risk of bias in included studies

Details of the risk of bias assessment are provided in the Characteristics of included studies and summarised in Figure 2. We assessed both studies as being at an overall high risk of bias.

 FigureFigure 2. Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

 

Allocation

We considered both the Clarkson 2008 and the Coventry 1989 trial to be of low risk with respect to the random sequence generation and allocation concealment. In the former trial, sampling, randomisation and analysis were conducted at arm’s length from the study base by a remote Health Services Research Unit at the University of Aberdeen. Randomisation was carried out using minimisation, involving four practice-based variables: the deprivation category for the area of practice; the number of partners in the practice; the throughput of 11- to 13-year-olds; and the number of restorative sealant claims in 2002. As the dentists were recruited before randomisation occurred, this would reduce selection bias.

In the latter trial, a senior officer of the British Dental Association spun a coin to decide which one of each pair of areas should transfer to capitation and which should remain under fee-for-service. Again, the primary care dentists were recruited before randomisation.

 

Blinding

We judged the blinding of outcome assessors to represent a high potential for bias in both trials. In the Clarkson 2008 study, the primary care dentists acted as the outcome assessors after the patients had received the intervention.

In the Coventry 1989 trial, outcome assessors varied for different outcomes and for many, their measurement was undertaken by unblinded non-participant dentists.

 

Incomplete outcome data

We judged both trials to be unclear with respect to incomplete outcome data. Although there does not appear to be an imbalance of missing data across the fee-for-service and control arms in the Clarkson 2008 trial, the authors did not provide any analysis, although the data was stated to be analysed using the intention-to-treat principle.

In the Coventry 1989 trial, only nine capitation practices and two fee-for-service practices withdrew. The number of dental practices which dropped out was therefore very low (4.9%) in the capitation areas and 1.2% in the fee-for-service areas. However, it is not clear how many children were examined, or if there was an imbalance across the two arms.

 

Selective reporting

We were not able to judge whether all the prespecified primary outcomes were reported for either trial; we assessed both trials as unclear risk of bias for this domain.

 

Other potential sources of bias

The Clarkson 2008 trial was judged to be unclear with respect to other potential sources of bias. The baseline characteristics and baseline outcomes of the arms were not statistically different at the practice level, probably due to the minimisation process. However, there was a statistically significant lower proportion of children having at least one sealant treatment in their second permanent molars at baseline in the fee-for-service only arm and the fee-for-service and education arms compared to the education only and the control arms. Even so, the primary analysis adjusted for a number of variables including the number of sealants placed in first permanent molars pre-intervention, and found a statistically significant difference in favour of the dentists receiving fee-for-service remuneration. When baseline differences were not adjusted for, this did not reach statistical significance.

The Coventry 1989 trial was judged to represent a high risk of bias due to a lack of stratification at baseline. The baseline characteristics and baseline outcomes in a number of paired areas were unbalanced and a statistically significant difference was found in the level of reported dental caries. An analysis conducted after the trial had commenced found that the mean number of decayed missing and filled teeth in five- to six-year-olds and eight- to nine-year-olds was significantly greater in Salford compared to Doncaster and in Bromley compared to Wycombe; Salford and Bromley were both remunerated by capitation.

 

Effects of interventions

See:  Summary of findings for the main comparison Fee-for-service remuneration for encouraging fissure sealant placement for second permanent molars in 12- to 14-year-olds;  Summary of findings 2 Capitation remuneration compared to fee-for-service remuneration for encouraging routine continuing dental care of children

The two included studies were heterogenous and so we considered pooling of the data to be inappropriate. The results are presented separately in Summary of findings table 1 and Summary of findings table 2.

The primary outcomes of this review are measures of clinical activity, measures of health service utilisation, healthcare costs, and patient outcomes; the secondary outcomes are measures of non-clinical behaviour of primary care dentists, measures of dental practice profitability/income, and measures of unintended consequences.

The Clarkson 2008 study reported that there was a statistically significant increase in clinical activity among those incentivised with a fee-for-service payment compared with the control arm, when the model was adjusted for the deprivation category for the area of practice, the number of partners in the practice, the throughput of 11- to 13-year-olds, and the number of restorative fissure sealants placed on first permanent molars at baseline. Using this model, the mean percentage of 12- to 14-year-olds receiving fissure sealants for second permanent molars was 9.8% higher (95% CI 1.8% to 17.8%) in the fee-for-service arm compared to the control arm. When left unadjusted, the difference in the mean percentage was 7.1%, which was not statistically significant (95% CI -1.9% to 16.1%). No further measures of health service utilisation or patient outcomes were reported.

The incremental cost-effectiveness of the fee-for-service arm compared to the control arm was reported to be 0.10 i.e. for every extra GBP 1 spent there was a 0.1% increase in activity. Units were reported as "% change in outcome per £[GBP]", but no price year was provided, and the detail of the outcome measure was not specified, and can only be inferred to be sealant placement. This lack of precision represents a major flaw in the reporting of the study. Furthermore, the economic evaluation did not undertake any discounting, nor did it take into account the payments from the state (i.e. the fee-for-service payment), rather, it investigated the cost to practices (in terms of staff time and consumables) to avoid double-counting, and the costs to parents.

In terms of clinical activity, the Coventry 1989 study reported that, in each of the pairs of areas, the mean number of filled teeth per 0- to 15-year-olds and the mean percentage of 0- to 15-year-olds having one or more teeth extracted tended to be lower in capitation areas while the mean percentage of 0- to 15-year-olds receiving active preventive advice tended to be higher.

Regarding health service utilisation, in each of the pairs of areas, the mean number of visits per 0- to 15-year-old tended to be lower in capitation areas compared to fee-for-service areas.

Regarding healthcare costs, in each of the pairs of areas, the mean expenditure in GBP per 0- to 15-year-old tended to be higher in capitation areas compared to fee-for-service areas. However, the authors reported that the mean expenditures should only be considered as approximations, and there is bias that places the capitation arm at a disadvantage. In addition, participating dentists in capitation areas referred significantly more children to the Community Dental Service compared to dentists in fee-for-service areas, and the cost of treating the children in the Community Dental Service would not have been taken into account in the economic analysis.

In terms of patient outcomes, in each of the pairs of areas, the mean number of decayed teeth per 14- to 15-year-old tended to be higher in capitation areas compared to fee-for-service areas, although this was only statistically significant in one of the pairs of areas. The authors reported that dentists working under capitation arrangements restored carious teeth at a later stage in the disease process than those working under fee-for-service arrangements, but this delay did not appear to compromise dental health.

It is important to note that not all of these comparisons between the pairs of areas were reported as statistically significant and the unit of analysis (e.g. dentists, patients, parents and administrators) was often not the same as the unit of randomisation, leading to unit-of-analysis error, where P values are artificially small. In addition, the baseline mean decayed/missing/filled permanent teeth (DMFT) and DMFT in the pairs of areas were unbalanced in two of the four pairs, with all the significant differences favouring the fee-for-service areas i.e. dental health tended to be better in the fee-for-service areas.

In terms of the secondary outcomes of this review, the Clarkson 2008 study did not report any relevant outcomes. However, the Coventry 1989 study reported several. Dentists under the fee-for-service system were more likely to introduce innovations into their dental practices compared to dentists under the capitation system (69% versus 56%, P ≤ 0.01), and reported a greater temptation to over-prescribe using a 0 - 100 visual analogue scale (31.0 versus 16.1, P ≤ 0.01), although, conversely, dentists under the capitation system felt a greater temptation to under-prescribe (58.3 versus 37.7, P ≤ 0.01). These latter outcomes were self reported using a visual analogue scale that was not validated and they cannot be substantiated with an objective measure. Moreover, these pooled results from the four pairs of areas are problematic because the matched pairs of areas were very different from each other. Therefore, indicating where there were consistent trends in all pairs is more appropriate than testing the statistical significance of overall differences between capitation areas and fee-for-service areas.

 

Discussion

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms
 

Summary of main results

In the Clarkson 2008 trial, there was a statistically significant increase in clinical activity (placement of sealants) among those incentivised with a fee-for-service payment compared with the control arm, when the model was adjusted.

In the Coventry 1989 trial, dentists working under capitation arrangements restored carious teeth at a later stage in the disease process than fee-for-service controls, and visits, fillings and extractions tended to be lower in capitation areas compared to fee-for-service areas, while preventive advice tended to be given more frequently.

 

Overall completeness and applicability of evidence

The results of the Clarkson 2008 study need to be interpreted in the context of a high risk of bias and indirectness; the primary care dentists received the fee-for-service remuneration in the first six months of the study, whilst the data was collected for a further twelve months after the start of the trial. It is possible that the effects of the fee-for-service remuneration could have been attenuated if the data had been collected at the limit of this 18-month data period.

The clinical relevance of placing fissure sealants on thirteen-year-olds may also have had an impact on the decision to treat. It is good practice to place sealants on teeth as soon as it is possible to provide moisture control for the erupting tooth. Second molars erupt at twelve years of age, yet the average age at baseline was 13.2 years in the education arm and 13.3 years in both the fee-for-service and education arm. The data was also collected for 18 months. Again, the percentage of children with fissure sealants at the end of the study may have been attenuated by this and in high risk children, restorations may have already been indicated rather than sealants. Finally, there was imprecision as the sample size was lower than the required sample size calculated by the authors. While the adjusted mean percentage difference for 12- to 14-year-olds receiving fissure sealants for second permanent molars was 9.8% higher in the fee-only group, the 95% CIs intervals were wide, with the lower boundary showing an increase of 1.8%. The clinical significance and cost-effectiveness of a financial payment that results in an increase of 1.8% in the number of children receiving fissure sealants is difficult to determine. In addition, given that the study was conducted in the four most deprived areas of Scotland the applicability of the findings to other settings may be limited.

In the Coventry 1989 trial, the researchers did not stratify the participants, based on disease experience at baseline and there were significantly different disease levels across a number of the paired arms, in addition to unit of analysis error. This means that it was not possible to determine the impact that the remuneration systems had on the health of the children, nor determine the cost-effectiveness of either arm, given the unknown impact on patient outcomes. 

Another limitation of the review is the inclusion criteria regarding study design. Major advances in econometrics have been made, which make it possible to draw causal inferences from non-random assignments of patients and dentists, for example, as demonstrated by Chalkley 2008. These studies could be considered and triangulated with experimental evidence to fully inform the evidence base. Future updates of this review may also consider broadening the inclusion criteria to consider data from non-experimental sources.

 

Quality of the evidence

The number of studies using an experimental design was very low. Both included studies had a high risk of bias and the quality of the evidence from the two included studies was low/very low for all outcomes, as assessed by GRADE.

 

Potential biases in the review process

Bias in the review process was kept to a minimum. Three authors (PRB, AMG and JP) screened the titles and determined inclusion, assessed for bias and extracted the data. Any differences were resolved by discussion. No post hoc changes were made to the review methods described in the protocol.

One area which may introduce bias is the choice of grey literature sources. The identified sources do not represent a comprehensive list of international health economics centres and is unclear as to whether this would have introduced some form of reporting bias within the review. Future updates of the review will aim to identify further relevant sources of both published and unpublished papers.

 

Agreements and disagreements with other studies or reviews

An examination of the health economic literature would suggest that a retrospective cost-based system like fee-for-service shifts the cost of care to the third party payer and creates an incentive for over-provision of services, as activity generates revenue. In contrast, prospective payment systems are said to cut the link between the revenue per case and create an incentive for under-provision, with a restriction of services largely to those with low needs (cream-skimming), the "dumping" of high cost patients and the "skimping" or under-provision for those with high needs (Ellis 1997; Krasnik 1990).

In Gosden et al's review, fee-for-service payments were associated with an increase in the quantity of primary care services, but changes to patient outcomes were equivocal and there was considerable variation in the study setting and the range of outcome measures utilised (Gosden 2000). In Scott et al's review, there was insufficient evidence to determine the impact of financial incentives on the quality of primary health care and the quality of the included studies was considered poor (Scott 2011). Flodgren et al's overview of reviews concluded that financial incentives may be effective in changing healthcare professional practice, but the included studies were of low to moderate quality and there were no studies evaluating patient outcomes (Flodgren 2011).

 

Authors' conclusions

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

 

Implications for practice

There is limited evidence that retrospective payment systems (fee-for-service) increase the clinical activity of primary care dentists, but it was not possible to determine whether this impacted on patient outcomes. The quality of the evidence from the two included studies was low/very low for all outcomes and the studies focused on levels of activity and throughput, rather than its distribution.

 
Implications for research

Further experimental research in this area is highly recommended given the paucity of evidence, and particular attention should be paid to patient outcomes. Future studies need to consider the level of payment, as well as the methods of remuneration. Investigating the effect of changing the remuneration method from one form to another is as important as studying different payment mechanisms in isolation. In addition, future studies should take the clinical context into account, with careful alignment of the incentives with patients' care needs.

The use of CBA and ITS studies as part of a natural experiment is warranted. In addition, major advances in econometrics have been made, which make it possible to draw causal inferences from non-random assignments of patients and dentists; these should be considered alongside and triangulated with experimental evidence to fully inform the evidence base.

 

Acknowledgements

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

The team would like to thank the Cochrane Oral Health Group and the Department of Dental Public Health and Primary Care Dentistry, for their contribution and support. We would also like to thank Mohammad Khoshnevisan, Paul Beirne and Tony Scott for their helpful comments during the peer review process along with Gill Leng and Luke Vale from the EPOC group.

 

Data and analyses

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

This review has no analyses.

 

Appendices

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms
 

Appendix 1. Search strategies

MEDLINE (OVID)

Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations and Ovid MEDLINE(R) <1946 to Present>

Search date: 11 June 2013

1 (dentist$ and (reimburs$ or pay or payment? or copay$ or "co-pay$" or remunerat$ or fee or fees)).ti. [Screen all]

2 Fees, Dental/

3 Dentists/ec [economics]

4 (dental or dentist$).ti,hw. and (billing? or co-insur$ or coinsur$ or co-pay$ or copay$ or deductible? or earning? or fee or fees or financial or income? or pay or pays or payor? or payee? or payment? reimburs$ or remunerat$ or salary or salarie? or financial incent$ or pay or payment? or "per capita").ti.

5 (dental or dentist$).ti,hw. and ((billing or co-insur$ or coinsur$ or co-pay$ or copay$ or deductible? or fee or fees or financial or pay or pays or payor? or payee? or payment or reimburs$ or remunerat$) adj3 (incentiv$ or coverage or insurance? or patient? or plan? or model or mechanism? or structure? or user?)).ab.

6 ((dental or dentist$) adj3 (billing? or earning? or fee or fees or income? or reimburs$ or remunerat$ or salary or salarie? or financial incent$ or pay or payment? or "per capita")).ab.

7 (exp Dentists/ or General practice, dental/) and (Income/ or Financ$.ti,hw. or (fee or fees or payment? or billing).ti,ab,hw.)

8 (exp Dentists/ or General practice, dental/) and (economic$ or payment? or reimbursement?).ti,ab,hw.

9 (exp Dentists/ or General Practice, Dental/) and (exp Financial Management/ or "insurance, dental"/)

10 (Dental Care/ or Dental Care for Aged/ or Dental Care for Children/ or Dental Care for Chronically Ill/ or Dental Care for Disabled/) and (fee or fees or payment? or pay or reimburs$ or billling or copay$ or "co-pay$").ti,ab.

11 (exp Diagnosis Oral/ or exp Dental Prophylaxis/ or exp Tooth Preparation/) and (fee or fees or payment? or pay or reimburs$ or billling or copay$ or "co-pay$").ti,ab.

12 "Salaries and Fringe Benefits"/ and (dentist$.ti. or *Dentists/ or General practice, dental/)

13 Partnership Practice, Dental/ec, og or Dentist's Practice Patterns/ec, og or exp Dental Care/ec, og or Dentistry/og

14 or/2-13 [Dentists & Finance/Reimb Terms]

15 exp *Dentists/

16 General Practice, Dental/ or Dentist's Practice Patterns/

17 Practice Management, Dental/

18 Preventive Dentistry/ or Public Health Dentistry/ or State Dentistry/

19 (dentistry or ((dental or dentist$) and (general or practice or practitioner?))).ti.

20 (general dental adj2 (practice or practitioner? or doctor?)).ti,ab.

21 ((general or family or primary care) adj2 dentistry).ab.

22 (dentist? or dentistry).ti,hw. and (general practice or general practitioner? or general dental).ti,ab.

23 ((dentist$ or dental).ti,hw. and generalist?.ti.) or ((dental or dentist$) adj3 generalist?).ab.

24 or/15-23 [Dentists/Dental Practice/Dentistry]

25 "fees and charges"/ or capitation fee/ or fee-for-service plans/ or fees, medical/ or "rate setting and review"/

26 insurance, health, reimbursement/ or reimbursement mechanisms/ or fee-for-service plans/ or blue cross blue shield insurance plans/ or "physician payment review commission"/ or prospective payment system/ or reimbursement, incentive/

27 exp economics, dental/

28 (capitation? or co-pay$ or copay$ or fee or fees or pay or payer? or payment? or reimburs$ or remunerat$ or salaries or salaried or salary).ti.

29 (remunerat$ or reimburs$).ab.

30 (fixed salar$ or fixed payment? or fixed fee or fixed fees or fee-for-service or pay-for-performance or cap$ fee? or capitation or dental fee? or medical fee? or co-pay$).ab.

31 ((pay or reimburs$ or financial or salary or "per capita" or remunerat$) adj2 (algorithm? or incentiv$ or model? or structur$ or incenti$ or "per capita")).ti,ab.

32 financial management/

33 ("accounts payable and receivable"/ or financial audit/ or "patient credit and collection"/) and (innovat$ or model? or strategy or strategies).ti,ab.

34 or/25-33 [Payment/Reimbursement]

35 (pre-trial? or post-trial?).ti,ab.

36 intervention?.ti. or (intervention? adj6 (clinician? or collaborat$ or community or complex or DESIGN$ or doctor? or educational or family doctor? or family physician? or family practitioner? or financial or GP or general practice? or hospital? or impact? or improv$ or individuali?e? or individuali?ing or interdisciplin$ or multicomponent or multi-component or multidisciplin$ or multi-disciplin$ or multifacet$ or multi-facet$ or multimodal$ or multi-modal$ or personali?e? or personali?ing or pharmacies or pharmacist? or pharmacy or physician? or practitioner? or prescrib$ or prescription? or primary care or professional$ or provider? or regulatory or regulatory or tailor$ or target$ or team$ or usual care)).ab.

37 (pre-intervention? or preintervention? or "pre intervention?" or post-intervention? or postintervention? or "post intervention?").ti,ab. [added 2.4]

38 (hospital$ or patient?).hw. and (study or studies or care or health$ or practitioner? or provider? or physician? or nurse? or nursing or doctor?).ti,hw.

39 demonstration project?.ti,ab.

40 (pre-post or "pre test$" or pretest$ or posttest$ or "post test$" or (pre adj5 post)).ti,ab.

41 (pre-workshop or post-workshop or (before adj3 workshop) or (after adj3 workshop)).ti,ab.

42 trial.ti. or ((study adj3 aim?) or "our study").ab.

43 (before adj10 (after or during)).ti,ab.

44 ("quasi-experiment$" or quasiexperiment$ or "quasi random$" or quasirandom$ or "quasi control$" or quasicontrol$ or ((quasi$ or experimental) adj3 (method$ or study or trial or design$))).ti,ab,hw. [ML]

45 ("time series" adj2 interrupt$).ti,ab,hw. [ML]

46 (time points adj3 (over or multiple or three or four or five or six or seven or eight or nine or ten or eleven or twelve or month$ or hour? or day? or "more than")).ab.

47 pilot.ti.

48 Pilot projects/ [ML]

49 (clinical trial or controlled clinical trial or multicenter study).pt. [ML]

50 (multicentre or multicenter or multi-centre or multi-center).ti.

51 random$.ti,ab. or controlled.ti.

52 (control adj3 (area or cohort? or compare? or condition or design or group? or intervention? or participant? or study)).ab. not (controlled clinical trial or randomized controlled trial).pt. [ML]

53 "comment on".cm. or review.ti,pt. or randomized controlled trial.pt. [ML]

54 review.ti. [EM]

55 (rat or rats or cow or cows or chicken? or horse or horses or mice or mouse or bovine or animal?).ti.

56 exp animals/ not humans.sh. [ML]

57 (or/36-52) not (or/53,55-56) [EPOC Methods Filter 2.4 Medline]

58 (randomized controlled trial or controlled clinical trial).pt. or randomized.ab. or placebo.ab. or clinical trials as topic.sh. or randomly.ab. or trial.ti.

59 exp animals/ not humans.sh.

60 58 not 59 [Cochrane RCT Filter 6.4.d Sens/Precision Maximizing]

61 14 or (24 and 34) [Dentists & Reimbursement]

62 61 and 60 [RCT]

63 (and/57,61) not 62 [EPOC]

64 1 not (or/62-63) [TI KW]

EMBASE (OVID)

Database: Embase Classic+Embase <1947 to July 17 2012>

Search date: 11 June 2013

1 (dentist$ and (reimburs$ or pay or payment? or copay$ or "co-pay$" or remunerat$ or fee or fees)).ti.

2 (patient? adj2 pay$).ab. and (dentist? or dental).ti,ab. [add to ML]

3 or/1-2 [KW screen all, no filters]

4 Fees, Dental/

5 (dental or dentist$).ti,hw. and (billing? or co-insur$ or coinsur$ or co-pay$ or copay$ or deductible? or earning? or fee or fees or financial or income? or pay or pays or payor? or payee? or payment? reimburs$ or remunerat$ or salary or salarie? or financial incent$ or pay or payment? or "per capita").ti.

6 (dental or dentist$).ti,hw. and ((billing or co-insur$ or coinsur$ or co-pay$ or copay$ or deductible? or fee or fees or financial or pay or pays or payor? or payee? or payment or reimburs$ or remunerat$) adj3 (incentiv$ or coverage or insurance? or patient? or plan? or model or mechanism? or structure? or user?)).ab.

7 ((dental or dentist$) adj3 (billing? or earning? or fee or fees or income? or reimburs$ or remunerat$ or salary or salarie? or financial incent$ or pay or payment? or "per capita")).ab.

8 or/4-7 [Dentists & Finance/Reimb --KW combine with filters]

9 (dentistry or ((dental or dentist$) and (general or practice or practitioner?))).ti.

10 (general dental adj2 (practice or practitioner? or doctor?)).ti,ab.

11 ((general or family or primary care) adj2 dentistry).ab.

12 (dentist? or dentistry).ti,hw. and (general practice or general practitioner? or general dental).ti,ab.

13 ((dentist$ or dental).ti,hw. and generalist?.ti.) or ((dental or dentist$) adj3 generalist?).ab.

14 dentist/ or dental practice/ or exp *preventive dentistry/ or *dental procedure/ or *dental care/

15 or/9-14 [Dentists/Dentistry]

16 reimbursement/

17 fee/ or capitation fee/ or medical fee/ or prospective payment/ or prospective pricing/

18 physician income/ or health care financing/

19 *health economics/

20 (health insurance/ or blue cross blue shield/ or medicaid/ or medicare/ or national health insurance/ or private health insurance/ or *public health insurance/) and (model? or strategy or strategies or structure? or organi?ation$).ti,ab.

21 (capitation? or co-pay$ or copay$ or fee or fees or pay or payer? or payment? or reimburs$ or remunerat$ or salaries or salaried or salary).ti.

22 (remunerat$ or reimburs$).ti,ab.

23 (fixed salar$ or fixed payment? or fixed fee or fixed fees or fee-for-service or pay-for-performance or cap$ fee? or capitation or dental fee? or medical fee? or co-pay$).ab.

24 ((pay or reimburs$ or financial or salary or "per capita" or remunerat$) adj2 (algorithm? or incentiv$ or model? or structur$ or incenti$ or "per capita")).ti,ab.

25 (patient? adj3 (fee or fees or pay$)).ab. [Add to ML]

26 accounting/ and (innovat$ or model? or strategy or strategies or structure?).ti,ab.

27 (pay or payment? or fee or fees or copay$ or co-pay$).ab. or (or/16-26) [Payment/Reimbursement]

28 controlled clinical trial/ or controlled study/ or randomized controlled trial/ [EM]

29 (book or conference paper or editorial or letter or review).pt. not randomized controlled trial/ [Per BMJ Clinical Evidence filter]

30 (random sampl$ or random digit$ or random effect$ or random survey or random regression).ti,ab. not randomized controlled trial/ [Per BMJ Clinical Evidence filter]

31 (animal$ not human$).sh,hw.

32 28 not (or/29-31) [Trial filter per BMJ CLinical Evidence]

33 intervention?.ti. or (intervention? adj6 (clinician? or collaborat$ or community or complex or DESIGN$ or doctor? or educational or family doctor? or family physician? or family practitioner? or financial or GP or general practice? or hospital? or impact? or improv$ or individuali?e? or individuali?ing or interdisciplin$ or multicomponent or multi-component or multidisciplin$ or multi-disciplin$ or multifacet$ or multi-facet$ or multimodal$ or multi-modal$ or personali?e? or personali?ing or pharmacies or pharmacist? or pharmacy or physician? or practitioner? or prescrib$ or prescription? or primary care or professional$ or provider? or regulatory or regulatory or tailor$ or target$ or team$ or usual care)).ab.

34 (pre-intervention? or preintervention? or "pre intervention?" or post-intervention? or postintervention? or "post intervention?").ti,ab. [added 2.4]

35 (hospital$ or patient?).hw. and (study or studies or care or health$ or practitioner? or provider? or physician? or nurse? or nursing or doctor?).ti,hw.

36 demonstration project?.ti,ab.

37 (pre-post or "pre test$" or pretest$ or posttest$ or "post test$" or (pre adj5 post)).ti,ab.

38 (pre-workshop or post-workshop or (before adj3 workshop) or (after adj3 workshop)).ti,ab.

39 trial.ti. or ((study adj3 aim?) or "our study").ab.

40 (before adj10 (after or during)).ti,ab.

41 ("quasi-experiment$" or quasiexperiment$ or "quasi random$" or quasirandom$ or "quasi control$" or quasicontrol$ or ((quasi$ or experimental) adj3 (method$ or study or trial or design$))).ti,ab,hw. [ML]

42 ("time series" adj2 interrupt$).ti,ab,hw. [ML]

43 (time points adj3 (over or multiple or three or four or five or six or seven or eight or nine or ten or eleven or twelve or month$ or hour? or day? or "more than")).ab.

44 pilot.ti.

45 Pilot projects/ [ML]

46 (clinical trial or controlled clinical trial or multicenter study).pt. [ML]

47 (multicentre or multicenter or multi-centre or multi-center).ti.

48 random$.ti,ab. or controlled.ti.

49 (control adj3 (area or cohort? or compare? or condition or design or group? or intervention? or participant? or study)).ab. not (controlled clinical trial or randomized controlled trial).pt. [ML]

50 "comment on".cm. or review.ti,pt. or randomized controlled trial.pt. [ML]

51 review.ti. [EM]

52 (rat or rats or cow or cows or chicken? or horse or horses or mice or mouse or bovine or animal?).ti.

53 exp animals/ not humans.sh. [ML]

54 (animal$ not human$).sh,hw. [EM]

55 *experimental design/ or *pilot study/ or quasi experimental study/ [EM]

56 ("quasi-experiment$" or quasiexperiment$ or "quasi random$" or quasirandom$ or "quasi control$" or quasicontrol$ or ((quasi$ or experimental) adj3 (method$ or study or trial or design$))).ti,ab. [EM]

57 ("time series" adj2 interrupt$).ti,ab. [EM]

58 (or/33-44,47-49) or experimental design/ or between groups design/ or quantitative methods/ or quasi experimental methods/ [PsycInfo]

59 exp animals/ or animal?.ti,id,hw. [PsycInfo]

60 (or/33-49) not (or/50,52-53) [EPOC Methods Filter 2.4 Medline]

61 (or/33-40,43-44,47-48,55-57) not (or/51,54) [EPOC Methods Filter 2.4 EMBASE]

62 58 not (or/51-52,59) [EPOC Methods Filter 2.4 PsycInfo]

63 8 or (15 and 27) [Dentists & Reimbursement]

64 63 and 32 [RCT]

65 (and/61,63) not 64 [EPOC]

66 3 not (or/64-65) [TI KW]

The Cochrane Library (OVID)

EBM Reviews - Cochrane Central Register of Controlled Trials <July 2012>, EBM Reviews - Cochrane Database of Systematic Reviews <2005 to July 2012>, EBM Reviews - Database of Abstracts of Reviews of Effects <3rd Quarter 2012>, EBM Reviews - Health Technology Assessment <3rd Quarter 2012>, EBM Reviews - NHS Economic Evaluation Database <3rd Quarter 2012>

Search Date 11 June 2013

--------------------------------------------------------------------------------

1 ((dental or dentist$) and (billing? or co-insur$ or coinsur$ or co-pay$ or copay$ or deductible? or earning? or fee or fees or financial or income? or pay or pays or payor? or payee? or payment? reimburs$ or remunerat$ or salary or salarie? or financial incent$ or pay or payment? or "per capita")).ti.

2 (dental or dentist$).ti,hw. and ((billing or co-insur$ or coinsur$ or co-pay$ or copay$ or deductible? or fee or fees or financial or pay or pays or payor? or payee? or payment or reimburs$ or remunerat$) adj3 (incentiv$ or coverage or insurance? or patient? or plan? or model or mechanism? or structure? or user?)).ab,kw.

3 ((dental or dentist$) adj3 (billing? or co-pay$ or copay$ or earning? or fee or fees or income? or reimburs$ or remunerat$ or salary or salarie? or financial incent$ or pay or payment? or "per capita")).ab.

4 or/1-3 [Dentists-Reimbursement]

5 (dentist$ or dental practice? or dental practitioner? or (dental$ adj2 provider?)).ti,ab,kw.

6 General Practice, Dental/ or Dentist's Practice Patterns/

7 Practice Management, Dental/

8 Preventive Dentistry/ or Public Health Dentistry/ or State Dentistry/

9 or/5-8 [Dentists]

10 "fees and charges"/ or capitation fee/ or fee-for-service plans/ or fees, medical/ or "rate setting and review"/

11 insurance, health, reimbursement/ or reimbursement mechanisms/ or fee-for-service plans/ or blue cross blue shield insurance plans/ or "physician payment review commission"/ or prospective payment system/ or reimbursement, incentive/

12 exp economics, dental/

13 (remunerat$ or reimburs$).ti,ab,kw.

14 (capitation? or co-pay$ or copay$ or fee or fees or fixed salar$ or pay or pays or payer? or payment? or salaries or salaried or salary).ti,ab,kw.

15 ((economic or financial or "per capita") adj3 (algorithm? or incentiv$ or model? or structur$ or incenti$ or "per capita")).ti,ab,kw.

16 financial management/

17 ((accounts adj2 (pay$ or receiv$)) or financial audit$ or ((credit or fee or fees or pay$) adj3 collect$)).ti,ab,kw.

18 or/10-17 [Reimbursement Terms]

19 4 or (and/9,18) [Results search date August 9-2012]

20 from 19 keep 1-26 [Trials]

21 from 19 keep 27 [CDSR]

22 from 19 keep 28 [DARE]

23 from 19 keep 29 [HTA]

24 from 19 keep 30 [ECON]

Cochrane Database of Systematic Reviews and DARE, NHS EED, HTA, MTH (WILEY)

Search date: 11 June 2013

CINAHL (Ebsco)

Search date: 11 June 2013


#Query

S67s1 NOT ( s65 or s66 ) [TI KW]

S66( s56 and s64 ) NOT s65 [EPOC results]

S65(s13 or (s21 and s30)) AND (S63 and S64) [RCT results]

S64s13 or (s21 and s30) [Dentists & Reimbursements]

S63S57 or S58 or S59 or S60 or S61 or S62 [RCT Filter]

S62TI ( “control* N1 clinical” or “control* N1 group*” or “control* N1 trial*” or “control* N1 study” or “control* N1 studies” or “control* N1 design*” or “control* N1 method*” ) or AB ( “control* N1 clinical” or “control* N1 group*” or “control* N1 trial*” or “control* N1 study” or “control* N1 studies” or “control* N1 design*” or “control* N1 method*” )

S61TI controlled or AB controlled

S60TI random* or AB random*

S59TI ( “clinical study” or “clinical studies” ) or AB ( “clinical study” or “clinical studies” )

S58(MM "Clinical Trials+")

S57TI ( (multicent* n2 design*) or (multicent* n2 study) or (multicent* n2 studies) or (multicent* n2 trial*) ) or AB ( (multicent* n2 design*) or (multicent* n2 study) or (multicent* n2 studies) or (multicent* n2 trial*) )

S56S32 or S33 or S34 or S35 or S36 or S37 or S38 or S39 or S40 or S41 or S42 or S43 or S44 or S45 or S46 or S47 or S48 or S49 or S50 or S51 or S52 or S53 or S54 or S55 [EPOC Filter]

S55TI ( (time points n3 over) or (time points n3 multiple) or (time points n3 three) or (time points n3 four) or (time points n3 five) or (time points n3 six) or (time points n3 seven) or (time points n3 eight) or (time points n3 nine) or (time points n3 ten) or (time points n3 eleven) or (time points n3 twelve) or (time points n3 month*) or (time points n3 hour*) or (time points n3 day*) or (time points n3 "more than") ) or AB ( (time points n3 over) or (time points n3 multiple) or (time points n3 three) or (time points n3 four) or (time points n3 five) or (time points n3 six) or (time points n3 seven) or (time points n3 eight) or (time points n3 nine) or (time points n3 ten) or (time points n3 eleven) or (time points n3 twelve) or (time points n3 month*) or (time points n3 hour*) or (time points n3 day*) or (time points n3 "more than") )

S53TI ( multicentre or multicenter or multi-centre or multi-center ) or AB random*

S52TI random* OR controlled

S51TI ( trial or (study n3 aim) or "our study" ) or AB ( (study n3 aim) or "our study" )

S50TI ( pre-workshop or preworkshop or post-workshop or postworkshop or (before n3 workshop) or (after n3 workshop) ) or AB ( pre-workshop or preworkshop or post-workshop or postworkshop or (before n3 workshop) or (after n3 workshop) )

S49TI ( demonstration project OR demonstration projects OR preimplement* or pre-implement* or post-implement* or postimplement* ) or AB ( demonstration project OR demonstration projects OR preimplement* or pre-implement* or post-implement* or postimplement* )

S48(intervention n6 clinician*) or (intervention n6 community) or (intervention n6 complex) or (intervention n6 design*) or (intervention n6 doctor*) or (intervention n6 educational) or (intervention n6 family doctor*) or (intervention n6 family physician*) or (intervention n6 family practitioner*) or (intervention n6 financial) or (intervention n6 GP) or (intervention n6 general practice*) Or (intervention n6 hospital*) or (intervention n6 impact*) Or (intervention n6 improv*) or (intervention n6 individualize*) Or (intervention n6 individualise*) or (intervention n6 individualizing) or (intervention n6 individualising) or (intervention n6 interdisciplin*) or (intervention n6 multicomponent) or (intervention n6 multi-component) or (intervention n6 multidisciplin*) or (intervention n6 multi-disciplin*) or (intervention n6 multifacet*) or (intervention n6 multi-facet*) or (intervention n6 multimodal*) or (intervention n6 multi-modal*) or (intervention n6 personalize*) or(intervention n6 personalise*) or (intervention n6 personalizing) or (intervention n6 personalising) or (intervention n6 pharmaci*) or (intervention n6 pharmacist*) or (intervention n6 pharmacy) or (intervention n6 physician*) or (intervention n6 practitioner*) Or (intervention n6 prescrib*) or (intervention n6 prescription*) or (intervention n6 primary care) or (intervention n6 professional*) or (intervention* n6 provider*) or (intervention* n6 regulatory) or (intervention n6 regulatory) or (intervention n6 tailor*) or (intervention n6 target*) or (intervention n6 team*) or (intervention n6 usual care)

S47TI ( collaborativ* or collaboration* or tailored or personalised or personalized ) or AB ( collaborativ* or collaboration* or tailored or personalised or personalized )

S46TI pilot

S45(MH "Pilot Studies")

S44AB "before-and-after"

S43AB time series

S42TI time series

S41AB ( before* n10 during or before n10 after ) or AU ( before* n10 during or before n10 after )

S40TI ( (time point*) or (period* n4 interrupted) or (period* n4 multiple) or (period* n4 time) or (period* n4 various) or (period* n4 varying) or (period* n4 week*) or (period* n4 month*) or (period* n4 year*) ) or AB ( (time point*) or (period* n4 interrupted) or (period* n4 multiple) or (period* n4 time) or (period* n4 various) or (period* n4 varying) or (period* n4 week*) or (period* n4 month*) or (period* n4 year*) )

S39TI ( ( quasi-experiment* or quasiexperiment* or quasi-random* or quasirandom* or quasi control* or quasicontrol* or quasi* W3 method* or quasi* W3 study or quasi* W3 studies or quasi* W3 trial or quasi* W3 design* or experimental W3 method* or experimental W3 study or experimental W3 studies or experimental W3 trial or experimental W3 design* ) ) or AB ( ( quasi-experiment* or quasiexperiment* or quasi-random* or quasirandom* or quasi control* or quasicontrol* or quasi* W3 method* or quasi* W3 study or quasi* W3 studies or quasi* W3 trial or quasi* W3 design* or experimental W3 method* or experimental W3 study or experimental W3 studies or experimental W3 trial or experimental W3 design* ) )

S38TI pre w7 post or AB pre w7 post

S37MH "Multiple Time Series" or MH "Time Series"

S36TI ( (comparative N2 study) or (comparative N2 studies) or evaluation study or evaluation studies ) or AB ( (comparative N2 study) or (comparative N2 studies) or evaluation study or evaluation studies )

S35MH Experimental Studies or Community Trials or Community Trials or Pretest-Posttest Design + or Quasi-Experimental Studies + Pilot Studies or Policy Studies + Multicenter Studies

S34TI ( pre-test* or pretest* or posttest* or post-test* ) or AB ( pre-test* or pretest* or posttest* or "post test* ) OR TI ( preimplement*" or pre-implement* ) or AB ( pre-implement* or preimplement* )

S33TI ( intervention* or multiintervention* or multi-intervention* or postintervention* or post-intervention* or preintervention* or pre-intervention* ) or AB ( intervention* or multiintervention* or multi-intervention* or postintervention* or post-intervention* or preintervention* or pre-intervention* )

S32(MH "Quasi-Experimental Studies")

S31TI ( (pre-trial? or post-trial?) ) OR AB ( (pre-trial? or post-trial?) )

S30S22 or S23 or S24 or S25 or S26 or S27 or S28 or S29

S29MH financial management

S28AB ( (pay or reimburs* or financial or salary or "per capita" or remunerat*) N2 (algorithm? or incentiv* or model? or structur* or incenti* or "per capita") ) OR TI ( (pay or reimburs* or financial or salary or "per capita" or remunerat*) N2 (algorithm? or incentiv* or model? or structur* or incenti* or "per capita") )

S27AB fixed salar* or fixed payment? or fixed fee or fixed fees or fee-for-service or pay-for-performance or cap* fee? or capitation or dental fee? or medical fee? or co-pay*

S26AB remunerat* or reimburs*

S25TI capitation? or co-pay* or copay* or fee or fees or pay or payer? or payment? or reimburs* or remunerat* or salaries or salaried or salary

S24MH economics, dental+

S23MH insurance, health, reimbursement OR MH reimbursement mechanisms OR MH fee for service plans OR MH prospective payment system OR MH reimbursement, incentive

S22MH ( "fees and charges" ) OR MH capitation fee OR MH fee for service plans OR MH ( "rate setting and review" )

S21S14 or S15 or S16 or S17 or S18 or S19 or S20

S20( ( TI (dentist* or dental) or MW (dentist* or dental) ) AND TI generalist? ) AND AB ( (dental or dentist*) N3 generalist? )

S19( TI (dentist? or dentistry) or MW (dentist? or dentistry) ) AND ( TI (general practice or general practitioner? or general dental) or AB (general practice or general practitioner? or general dental) )

S18AB (general or family or primary care) N2 dentistry

S17TI ( general dental N2 (practice or practitioner? or doctor?) ) OR AB ( general dental N2 (practice or practitioner? or doctor?) )

S16TI dentistry or ((dental or dentist*) and (general or practice or practitioner?))

S15MH Preventive Dentistry OR MH Public Health Dentistry

S14MH Dentists+

S13S2 or s3 or s4 or s5 or s6 or s7 or s8 or s9 or s10 or s11 or s12

S12(MH "Dental Care+/OG/EC") OR MH "Dentistry/OG"

S11MH ( "Salaries and Fringe Benefits" ) AND ( TI dentist* or MH *Dentists )

S10MH ( Diagnosis Oral+ or Dental Prophylaxis+ ) AND ( TI (fee or fees or payment? or pay or reimburs* or billling or copay* or "co-pay*") or AB (fee or fees or payment? or pay or reimburs* or billling or copay* or "co-pay*") )

S9MH ( Dental Care or Dental Care for Aged or Dental Care for Children or Dental Care for Chronically Ill or Dental Care for Disabled ) AND ( TI (fee or fees or payment? or pay or reimburs* or billling or copay* or "co-pay*") or AB (fee or fees or payment? or pay or reimburs* or billling or copay* or "co-pay*") )

S8MH Dentists+ AND MH ( Financial Management+ or "insurance, dental" )

S7MH Dentists+ AND (TI(economic* or payment? or reimbursement?) or AB (economic* or payment? or reimbursement?) or MW (economic* or payment? or reimbursement?))

S6MH Dentists+ AND ( (TI (Income/ or Financ*) or MW (Income/ or Financ*)) or (TI(fee or fees or payment? or billing) or AB (fee or fees or payment? or billing) or MW (fee or fees or payment? or billing)) )

S5AB (dental or dentist*) N3 (billing? or earning? or fee or fees or income? or reimburs* or remunerat* or salary or salarie? or financial incent* or pay or payment? or "per capita")

S4( TI ( dental or dentist* ) OR MW ( dental or dentist* ) ) AND AB ( (billing or co-insur* or coinsur* or co-pay* or copay* or deductible? or fee or fees or financial or pay or pays or payor? or payee? or payment or reimburs* or remunerat*) N3 (incentiv* or coverage or insurance? or patient? or plan? or model or mechanism? or structure? or user?) )

S3( TI ( dental or dentist* ) OR MW ( dental or dentist* ) ) AND TI ( billing? or co-insur* or coinsur* or co-pay* or copay* or deductible? or earning? or fee or fees or financial or income? or pay or pays or payor? or payee? or payment? reimburs* or remunerat* or salary or salarie? or financial incent* or pay or payment? or "per capita" )

S2(MH "Dentists/EC")

S1TI dentist* and (reimburs* or pay or payment? or copay* or "co-pay*" or remunerat* or fee or fees)



EconLit, Dissertations & Theses (ProQuest)

Search date: 11 June 2013

all(dentist*) AND all(reimburs* OR remunerat* or pay OR payment* or financial or "co-pay*" or budget* or medicaid or HMO or fee or fees or "health maintenance organisation*" or "health maintenance organization*" or "preferred provider*" or "managed care")

PAIS International, Political Science, Worldwide Political Science Abstracts (ProQuest)

Search date: 11 June 2013

Searched for: ti(dentist* OR "dental care") AND (reimburs* OR remunerat* or pay OR payment* or financial or "co-pay*" or budget* or medicaid or HMO or fee or fees or "health maintenance organisation*" or "health maintenance organization*" or "preferred provider*" or "managed care")

Databases:ProQuest Dissertations & Theses (PQDT) ProQuest Dissertations & Theses (PQDT)

ti(dentist* OR "dental care") AND (reimburs* OR remunerat* or pay OR payment* or financial or "co-pay*" or budget* or medicaid or HMO or fee or fees or "health maintenance organisation*" or "health maintenance organization*" or "preferred provider*" or "managed care")

 

Appendix 2. Data extraction form

1) Clarkson 2008

Number of participants


DetailFee-for-service onlyControl

Number randomised Dentists: 37

Patients: 925
Dentists: 39

Patients: 957 

Number analysed Dentists: 33 (89.2%)

Patients: 698 (75.5%)
Dentists: 35 (89.7%)

Patients: 730 (76.3%)

Number not analysed and reasons Dentists:

  • Lost to follow-up
    • 4 (10.8%)
    • Reason: 2 dentists left the study and 2 refused to take part after randomisation


Patients:

  • Lost to follow-up:
    • 161 (17.4%)
    • Reason: Most of the children were patients of the dentists who were lost to follow-up but also there were 39 missing patient records
  • Excluded from analysis:
    • 66 (7.1%)
    • Reason: Lack of erupted second permanent molars
Dentists:

  • Lost to follow-up
    • 4 (10.3%)
    • Reason: 2 dentists left the study and 2 refused to take part after randomisation


Patients:

  • Lost to follow-up:
    • 127 (13.3%)
    • Reason: Most of the children were patients of the dentists who were lost to follow-up but also there were 48 missing patient records
  • Excluded from analysis:
    • 100 (10.4%)
    • Reason: Lack of erupted second permanent molars



Characteristics at baseline


DetailFee-for-service onlyControl

Dental practice-level variables for minimisation

Number of partners

Single-handed13 (39)14 (40)

Two/three partners10 (30)9 (26)

Four or more10 (30)12 (34)

Deprivation area of dental practice – n (%)

418 (55)16 (46)

58 (24)10 (29)

6/7 (most deprived)7 (21)9 (26)

Restorative fissure sealant claims 2002 - n (%)

None9 (27)11 (31)

1 - 510 (30)8 (23)

6 or more14 (42)16 (46)

Throughput 11- to 13-year-olds - n (%)

Low (48 - 95)9 (27)9 (26)

Medium (96 - 143)14 (42)11 (31)

High (> 143)10 (30)5 (43)

Other dental practice/dentist-level variables

Child patients with sealant on any second permanent molar – mean % (SD)32.8 (26.5)38.4 (28.9)

Child patients with sealant on any first permanent molar – mean % (SD)10.7 (16.6)13.4 (15.1)

Cluster size - median (interquartile range)19 (22, 24)20 (22, 24)

High population density (> 100 people/hectare) - n (%)8 (25)9 (25)

Hygienist in dental team - n (%)14 (42)16 (46)

Gender of dentist - n (%)

Female12 (36)15 (43)

Male21 (64)20 (36)

Dentist working part-time (< 9 sessions/week) - n (%)6 (19)6 (17)

Number of years qualified as a dentist - mean (SD)18.9 (8.6)19.7 (8.2)

Patient-level variables

Age of children - mean (SD)13.21 (0.96)13.24 (0.98)

Gender of children - n (%)

Female348 (49.9)368 (50.4)

Male350 (50.1)362 (49.6)

Deprivation area of dental practice – n (%)

4375 (53.7)334 (45.8)

5173 (24.8)220 (30.1)

6/7 (most deprived)150 (21.5)176 (24.1)

Sealant on any second permanent molar – n (%)75 (10.7)98 (13.4)

Sealant on any first permanent molar – n (%)229 (32.8)280 (38.4)

n: number of participants

SD: standard deviation



Methods and suitability of outcome assessment


OutcomeOutcome assessment

MethodComments

Mean percentage of 12- to 14-year-olds receiving fissure sealants for second permanent molars per dentist (weighted by number of children seen)Data collection forms were sent to dentists for completion using patient records

The dentists only received the fee-for-service remuneration in the first six months of the study but the data were collected 18 months after the start of the trial
Dentists may not keep accurate patient record cards, particularly if they prioritise treatment, which could be exacerbated under a fee-for-service remuneration system

The effects of the fee-for-service remuneration would have been attenuated if 18-month data were analysed

Incremental cost-effectiveness of fee-for-service vs. controlThe economic evaluation calculated incremental cost-effectiveness in terms of the "% change in outcome per £[GBP]". The costs included the costs of dentists’ time taken to seal two teeth (based on average earnings), the cost of consumables obtained from clinical guidelines and expert opinion of two experienced practitioners, the cost of hygienist or dental nurse time and costs to parents (travel costs, out-of-pocket costs, and the time costs incurred by parents travelling to a sample of dentists, which were collected from questionnaires handed to parents at dental practices and used to calculate an average cost per child). The outcome in the ICER is not explicitly stated and so can only be assumed to be sealant placement. In order to avoid double-counting, the fees paid to the dentists were excluded as they represent transfer payments from the state (i.e. the study funds; the shadow cost of public funds due to the collection of taxes raised to fund the fees is ignored) and the cost of the dentists’ time was already included. The marginal costs of administering any new fee were investigated and assumed to be negligible. The intervention costs also included education and trainingThe economic evaluation does not involve a follow-up of fissure sealant retention or cost savings due to prevention of dental diseases

Futhermore, the evaluation does not take into account the payments from the state (i.e. the fee-for-service remuneration) so the only costs taken into account are the costs to the parents and to the dental practices (in terms of staff time and consumables). An alternative perspective would be to investigate the cost-effectiveness from the point of view of the state, which pays the fee-for-service (in place of the dental practices), and the parents

GBP: Pound Sterling
ICER: incremental cost-effectiveness ratio



Methods and suitability of analysis


OutcomeAnalysis

MethodComments

Mean percentage of 12- to 14-year-olds receiving fissure sealants for second permanent molars per dentist (weighted by number of children seen)The primary analysis used analysis of covariance (ANCOVA) under the intention-to-treat principle and weighted by the number of patients seen per dentist. The ANCOVA analysis adjusted for the deprivation category of the area of the dental practice, the number of partners in practice, the throughput of 11- to 13-year-olds and the number of restorative fissure sealants placed on first permanent molars at baseline. However, it did not adjust for the percentage of children having at least one sealant treatment of second permanent molars at baseline even though there were lower percentages in the fee-for-service and both fee-for-service and education arms compared to the education and control arms, which could have an impact on the results

The authors stated that estimation of main effects (the risk difference for fee-for-service vs. no fee-for-service and education vs. no education) required 150 dentists assessing 25 children each for 80% power at a 5% significance level to detect a 15% difference from a 22% "baseline" control group level (Southwick 1999). This calculation assumed an intracluster correlation of 0.3 (the ‘cluster effect’). However, 149 dentists were randomised and data were collected from only 133 dentists, the median number of children per dentist was less than 25 (the mean was not reported) and the intracluster correlation was 0.315. The outcome for the control group (no fee-for-service) was 26.3% and the unadjusted risk difference for fee-for-service vs. no fee-for-service did not reach statistical significance (7.1, 95% CI -1.9 to 16.1). However, the adjusted risk difference did (9.8, 95% CI 1.8 to 17.8)
Due to the fact that the analysis was at the level of the dentists rather than the patients, the problem of lack of independence between observations from the same cluster does not arise. In addition, this approach avoids unit-of-analysis errors. However, aggregating patient-level variables to higher-order variables and then conducting an analysis at this higher level means that all within-group information is discarded (because it takes the average of the patient-level variable divided by one hundred to create a percentage) which can considerably reduce the power of the study

In order for ANCOVA to be effective, the covariate must be linearly related to the dependent variable, but no indication of whether the covariates were linearly related to the dependent variables is explicitly given, so this must be assumed

In addition, ANCOVA requires homogeneity-of-regression slopes. In this case, this assumption may not be met because the effect of fee-for-service remuneration on the percentage of children receiving fissure sealants for second permanent molars may be different between dentists working in areas with different levels of deprivation etc. i.e. there may be interaction terms involving the covariates and the fee-for-service variable. The authors stated that a sensitivity analysis with unadjusted outcomes confirmed the result of the primary ANCOVA analysis but the paper reported that the unadjusted risk difference for fee-for-service vs. no fee-for-service did not reach statistical significance (7.1, 95% CI -1.9 to 16.1) but the adjusted risk difference did (9.8, 95% CI 1.8 to 17.8). Multilevel models (before testing for differences between intervention arms) can be used as an alternative to ANCOVA because they have the advantages that they do not require the assumption of homogeneity-of-regression slopes and they are designed to deal with intraclass correlation, which would be necessary to consider if the analysis was at the level of the patients

The number of dentists randomised was lower than the number required to provide data on at least 25 children each, according to the authors' statement



Results


Detail Outcome Mean (SD)Risk difference for fee-for-service vs. no fee-for-service (95% confidence interval)


Fee-for-service onlyControlEducation onlyFee-for-service and educationFee-for service (all)No fee-for-service (all)AdjustedUnadjusted

Measures of clinical behaviour of PCDsMean percentage of 12- to 14-year-olds receiving fissure sealants for second permanent molars per dentist (weighted by number of children seen)35.1 (28.4)25.3 (25.5)27.4 (30.8)30.8 (23.1)32.9 (25.7)26.3 (28.0)9.8 (1.8 -17.8)7.1 (-1.9 - 16.1)

The model adjusted for the baseline dental practice-level covariates (deprivation category for the area of dental practice, number of partners in practice, throughput of 11- to 13-year-olds and the number of restorative fissure sealants placed on first permanent molars at baseline). The intracluster correlation is 0.315
PCD: primary care dentist
SD: standard deviation




Detail Outcome

Healthcare costsIncremental cost-effectiveness of fee-for-service vs. control (reported as the "% change in outcome per £[GBP]"). (The outcome in the ICER is not explicitly stated and so can only be assumed to be sealant placement)0.10

GBP: Pound Sterling
ICER: incremental cost-effectiveness ratio



2) Coventry 1989

Number of participants


DetailCapitationFee-for-service

Number randomised Health service administrative areas: 4 (Salford (S), Norfolk (N), Bromley (B), Grampian (G))Health service administrative areas: 4 (Doncaster (D), Hereford and Worcester (H), Wycombe (W), Fife (F))

Patients

14- to 15-year-olds

Total: 2980 (no breakdown of data between capitation and fee-for-service areas was reported)

5- to 6-year-olds

Total: 2980 (no breakdown of data between capitation and fee-for-service areas was reported)


Number analysed Dental practices:

Total: 183 (67%)

S: 25 (81%)

N: 90 (74%)

B: 29 (49%)

G: 39 (63%)

Dentists initially included:

Total: 322 (65%)

S: 50 (81%)

N: 144 (73%)

B: 62 (58%)

G: 66 (65%)

Patients

14- to 15-year-olds:

Total: 967

S: 250

N: 240

B: 236

G: 241

5- to 6-year-olds:

Total: 989

S: 247

N: 238

B: 251

G: 253
Dental practices:

Total: 171 (71%)

D: 30 (83%)

H: 68 (69%)

W: 40 (74%)

F: 33 (62%)

Dentists initially included:

Total: 366 (72%)

D: 75 (82%)

H: 138 (68%)

W: 90 (74%)

F: 63 (67%)

Patients:

14- to 15-year-olds:

Total: 952

D: 239

H: 225

W: 254

F: 234

5- to 6-year-olds:

Total: 949

D: 219

H: 251

W: 234

F: 245

Number not analysed and reasons Dental practices :

  • Lost to follow-up
    • 9 (4.9%)
    • Reason: It was found (in large group practices) to be difficult to control for the administration of all the forms involved and there were problems associated with transferring patients in these dental practices when there was a rapid turnover of associates, plus the exclusion of private practice for children was a problem
Dental practices :

  • Lost to follow-up
    • 2 (1.2%)
    • Reason: The dentists objected to the wording of the parent satisfaction questionnaire

Patients:

14- to 15-year-olds:

  • Lost to follow-up


    • 144
    • Reason: Children could not be contacted because they were no longer living at the addresses provided by the Dental Practice Boards and several other reasons which the authors did not report
    • 93
    • Reason: Parents refused consent
    • 549
    • Reason: Parents did not reply
    • 256
    • Reason: Children were not examined when examiners attended the children's schools (reason not reported)


5- to 6-year-olds: 2175

  • Lost to follow-up


    • 168
    • Reason: Children could not be contacted because they were no longer living at the addresses provided by the Dental Practice Boards and several other reasons which the authors did not report
    • 68
    • Reason: Parents refused consent
    • 569
    • Reason: Parents did not reply
    • 237
    • Reason: Children were not examined when examiners attended the children's schools (reason not reported)


The number of dentists varied over time as dentists joined and left dental practices, so the number of dental practices was the stable and primary parameter



Characteristics at baseline


DetailCapitationFee-for-service

Variables for matching pairs of areas

Mean number of fillings per course of treatment provided for 10- to 14-year-olds (calculated differently in England and Scotland)S:1.03

N: 0.67

B: 0.68

G: 0.62
D: 0.96

H: 0.66

W: 0.67

F: 0.69

Population per dentistS: 5041

N: 4029

B: 2657

G: 4010
D: 4629

H: 4000

W: 3286

F: 3588

Percentage of households with more than one person per room (calculated differently in England and Scotland)S: 4.1

N: 1.9

B: 2.4

G: 32.8
D: 3.2

H: 2.3

W: 2.4

F: 32.4

Fluoride in water supplyS: No

N: Yes

B: No

G: No
D: No

H: Yes

W: No

F: No

Patient-level variables with differences between the matched pairs

Mean dmft

5- to 6-year-oldsS: 3.6**

B: 1.3**
D: 2.8**

W: 0.8**

8- to 9-year-oldsS: 4.6*

B: 2.7**
D: 3.7*

W: 1.9**

Mean DMFT

8- to 9-year-oldsS: 0.9*

B: 0.3
D: 0.7*

W: 0.3

11- to 12-year-oldsS: 2.0*

B: 0.9
D: 1.6*

W: 1.0

14- to 15-year-oldsS: 4.5

B: 2.7
D: 4.1

W: 2.6

Dental practice/dentist-level variables with differences between the matched pairs (no consistent patterns were found across all four pairs)

Proportion of single-handed to group practicesB: lowerW: higher

Estimates submitted per dentistS: higherD: lower

Estimates for children only submitted per dentistsS: no difference

N: lower
D: no difference

H: higher

* P ≤ 0.05

** P ≤ 0.01
dmft: decayed/missing/filled primary teeth
DMFT: decayed/missing/filled permanent teeth
Health service administrative areas:
B: Bromley; D: Doncaster; F: Fife; G: Grampian; H: Hereford and Worcester; N: Norfolk; S: Salford; W: Wycombe



Methods and suitability of outcome assessment


OutcomeOutcome assessment

MethodComments

Dental health outcomes and healthcare cost outcomesN/AThere is a lack of descriptions of standards used in the examination process and limited description of how costs were obtained for the cost-effectiveness analysis (e.g. no time preference information is provided nor details regarding full economic costing (Mellor 1994)

Patterns of treatment outcome measuresA random sample of 25 dentists were asked to provide information about their treatment of a random sample of up to 90 of their patients. A statistical comparison of the data collection form and the information in a sample of patient records from each dentist showed substantial agreementDentists may not keep accurate patient record cards, particularly if they prioritise treatment, which could be exacerbated under a fee-for-service remuneration system

Mean values for temptation expressed by dentists to over-prescribe and to under-prescribe

Mean values of clinical freedom expressed by dentists
These outcome measures were measured on a visual analogue scale and there was no indication that they were validatedThe clinical significance of any differences found within matched pairs is unknown

Healthcare cost outcomesAll payments made to study dentists for the treatment of 0- to 5-year-olds during 1988 were divided by the estimated numbers of children treated. However, the estimated number is only an approximation as it was impossible to eliminate double-counting, particularly in the fee-for-service system

Participating dentists in capitation areas referred significantly more children to the Community Dental Service compared to dentists in fee-for-service areas; this is despite the fact that non-participating dentists in the capitation areas tended to refer significantly fewer children compared to non-participating dentists in fee-for-service areas
The mean expenditure per 0- to 15-year-old should only be considered as close approximations, and there is bias that places the capitation arm at a disadvantage

The cost of treating the children in the Community Dental Service would not have been taken into account in the economic analysis



Methods and suitability of analysis


OutcomeAnalysis

MethodComments

All outcome measuresThe study authors stated that they intended to treat each matched pair as separate, thus the overall study would contain four replicates under contrasting socioeconomic and environmental circumstances. However, the authors sometimes pooled the results of the replicates and occasionally tested the overall differences between capitation areas and fee-for-service areas for statistical significance (in addition to noting where there were consistent trends among the pairs)

Health Service administrative areas were the unit of randomisation, but not the unit of analysis
The matched pairs of areas were very different from each other, so indicating where there were consistent trends in all pairs is more appropriate than testing the statistical significance of overall differences between capitation areas and fee-for-service areas. In addition, there were many outcome measures, often assessed for numerous age groups and for each of the pairs of areas, which can lead to the 'multiple testing problem' for which techniques have been developed to control the false positive error rate

The unit of analysis (e.g. dentists, patients, parents and administrators) was often not the same as the unit of randomisation. This leads to unit-of-analysis error, where P values are artificially small (though the estimates of effect are unbiased), leading to false positive conclusions that the intervention had an effect



Results


Detail Outcome Mean

CapitationFee-for-service

Primary outcomes assessed

Measures of clinical behaviour of PCDsMean number of examinations per child

0- to 5-year-oldsAll: 1.5*

S: 1.6

B:1.4

N: 1.4

G: 1.5*
All: 1.7*

D: 1.7

W: 1.6

H: 1.6

F: 1.8*

6- to 12-year-oldsAll: 1.6*

S: 1.7

B: 1.6*

N: 1.6

G: 1.6*
All: 1.8*

D: 1.8

W:1.8*

H: 1.8

F: 1.9*

13- to 15-year-oldsAll: 1.6*

S: 1.7

B: 1.5*

N: 1.7

G: 1.5
All: 1.7*

D: 1.7

W: 1.7*

H: 1.7

F: 1.7

6- to 15-year-olds (sic)All: 1.6*

S: 1.7

B: 1.5*

N: 1.6

G: 1.5
All: 1.7*

D: 1.7

W: 1.7*

H: 1.7

F: 1.6

Mean number of teeth filled per child

0- to 5-year-oldsS: 0.30

B: 0.19

N: 0.16

G: 0.30*
D: 0.39

W: 0.17

H: 0.23

F: 0.49*

6- to 12-year-oldsS: 0.63*

B: 0.41

N: 0.53

G: 0.69
D: 0.89*

W: 0.43

H: 0.62

F: 0.90

13- to 15-year-oldsS: 0.87

B: 0.43

N: 0.63

G: 0.95
D: 1.06

W: 0.50

H: 0.84

F: 1.34

0- to 15-year-oldsS: 0.60*

B: 0.34

N: 0.44

G: 0.63*
D: 0.78*

W: 0.34

H: 0.44

F: 0.91*

Mean percentage of children having one or more teeth extracted

0- to 5-year-oldsS: 7

B: 1

N: 2

G: 8
D: 8

W: 1

H: 2

F: 7

6- to 12-year-oldsS: 19*

B: 7

N: 8*

G: 21
D: 28*

W: 10

H: 14*

F: 22

13- to 15-year-oldsS: 13

B: 12

N: 11

G: 13
D: 17

W: 9

H: 14

F: 16

0- to 15-year-oldsS: 13*

B: 7

N: 7*

G: 14
D: 18*

W: 7

H: 10*

F: 15

Mean percentage of children receiving active preventive advice

0- to 5-year-oldsTotal: 38*

S: 48*

B: 34*

N: 31

G: 41
Total: 21*

D: 14*

W: 14*

H: 32

F: 24

6- to 12-year-oldsTotal: 36

S: 47*

B: 36

N: 28

G: 34
Total: 27

D: 21*

W: 22

H: 35

F: 30

13- to 15-year-oldsTotal: 34

S: 43

B: 28

N: 28

G: 36
Total: 26

D: 23

W: 18

H: 34

F: 31

0- to 15-year-oldsTotal: 36*

S: 46*

B: 33

N: 29

G: 37
Total: 25*

D: 19*

W: 18

H: 34

F: 28

Mean percentage of children receiving a scaling

0- to 5-year-oldsAll: 16*

S: 24*

B: 18*

N: 13*

G: 12*
All: 39*

D: 46*

W: 30*

H: 31*

F: 48*

6- to 12-year-oldsAll: 26*

S: 28*

B: 30*

N: 26*

G: 22*
All: 58*

D: 62*

W: 55*

H: 49*

F: 69*

13- to 15-year-oldsAll: 36*

S: 35*

B: 38*

N: 38*

G: 34*
All: 65*

D: 69*

W: 57*

H: 62*

F: 73*

0- to 15-year-oldsAll: 26*

S: 29*

B: 28*

N: 25*

G: 23*
All: 54*

D: 59*

W: 48*

H: 47*

F: 63*

Mean percentage of children receiving one or more fissure sealants

6- to 12-year-oldsS: 8

B: 8

N: 4

G: 17*
D: 6

W: 4

H: 4

F: 10*

13- to 15-year-oldsS: 4

B: 4

N: 4

G: 8
D: 6

W: 3

H: 5

F: 4

6- to 15-year-oldsS: 6

B: 6

N: 4

G: 13
D: 6

W: 4

H: 4

F: 7

Mean percentage of children having radiographs

6- to 12-year-oldsS: 3

B: 1

N: 1

G: 0
D: 3

W: 1

H: 0

F: 1

13- to 15-year-oldsS: 8

B: 7

N: 7

G: 6
D: 13

W: 12

H: 11

F: 4

6- to 15-year-oldsS: 12

B: 14*

N: 18

G: 9
D: 19

W: 26*

H: 17

F: 13

0- to 15-year-oldsS: 8

B: 8*

N: 9

G: 5
D: 12

W: 13*

H: 10

F: 6

Percentage of participating dentists referring patients to the Community Dental Service (percentage of non-participating dentists referring patients to the Community Dental Service)27* (19*)19* (29*)

Percentage of dental practices arranging for in-practice emergency treatment of their patients out of routine surgery hours44**28**

Percentage of dental practices arranging for out of practice emergency treatment of their patients out of routine surgery hours56**72**

Measures of health service utilisationMean number of visits per child

0- to 5-year-oldsAll: 1.7*

S: 1.9

B: 1.5

N: 1.7

G: 1.7*
All: 1.9*

D: 2.0

W: 1.7

H: 1.8

F: 2.2*

6- to 12-year-oldsAll: 2.4*

S: 2.6*

B: 2.0*

N: 2.3

G: 2.5*
All: 2.8*

D: 2.9*

W: 2.6*

H: 2.5

F: 3.0*

13- to 15-year-oldsAll: 2.5*

S: 2.6*

B: 2.0*

N: 2.8

G: 2.6*
All: 3.1*

D: 3.4*

W: 2.7*

H: 3.1

F: 3.1*

0- to 15-year-oldsAll: 2.2*

S: 2.4*

B: 1.9*

N: 2.2

G: 2.3*
All: 2.6*

D: 2.8*

W: 2.3*

H: 2.5

F: 2.8*

Measures of patient outcomes14- to 15-year-olds

Percentage with caries on at least one toothS: 75

B: 58

N: 68

G: 77
D: 74

W: 57

H: 70

F: 81

Mean DMFTS: 3.3

B: 1.8

N: 2.6

G: 4.2
D: 3.0

W:1.9

H: 2.7

F: 4.4

Mean DMFT among regularly attending childrenS: 3.3

B: 1.8

N: 2.6

G: 4.1
D: 3.0

W: 1.9

H: 2.6

F: 4.2

Mean number of decayed teethS: 0.32

B: 0.31

N: 1.33**

G: 0.80
D: 0.16

W: 0.24

H: 0.58**

F: 0.65

Mean number of decayed teeth among regularly attending childrenS: 0.32

B: 0.31

N: 1.39**

G: 0.94
D: 0.16

W: 0.26

H: 0.59**

F: 0.61

Mean number of missing teethS: 0.16

B: 0.03

N: 0.05

G: 0.46
D: 0.12

W: 0.04

H: 0.08

F: 0.47

Mean number of missing teeth among regularly attending childrenS: 0.14

B: 0.04

N: 0.07

G: 0.45
D:0.11

W: 0.02

H: 0.08

F: 0.37

Mean number of sound filled teethS: 2.8

B: 1.4

N: 1.2*

G: 2.9
D: 2.8

W: 1.7

H: 2.0*

F: 3.3

Mean number of filled teeth among regularly attending childrenS: 2.8

B: 1.5

N: 1.1**

G: 2.8
D: 2.7

W: 1.6

H: 1.9**

F: 3.2

Mean number of sound and carious filled teethS: 2.9

B: 1.5

N: 1.5**

G: 3.0
D: 2.8

W: 1.7

H: 2.2**

F: 3.5

Percentage with at least one fissure sealantTotal: 18**

S: 10

B: 19

N: 13**

G: 31
Total: 22**

D: 14

W:19

H: 21**

F: 35

Percentage with at least one fissure sealant among regularly attending childrenS: 2.8

B: 1.5

N: 1.1**

G: 2.8
D: 2.7

W: 1.6

H: 1.9**

F: 3.2

5- to 6-year-olds

Percentage with caries on at least one toothS: 62

B: 26

N: 38

G: 51
D: 67

W: 31

H: 32

F: 62

Mean dmftS: 3.0

B: 0.9

N: 1.1

G: 2.6**
D: 3.0

W: 1.1

H: 1.1

F: 3.7**

Mean dmft among regularly attending childrenS: 2.8

B: 0.7

N: 1.1

G: 2.6
D: 3.2

W: 1.1

H: 0.8

F: 3.2

Mean number of decayed teethS: 2.0

B: 0.5

N: 0.6

G: 1.6*
D: 1.8

W: 0.7

H: 0.5

F: 2.0*

Mean number of decayed teeth among regularly attending childrenS: 2.0

B: 0.3*

N: 0.5

G: 1.5
D: 2.0

W: 0.7*

H: 0.4

F: 1.7

Mean number of missing teethS: 0.49

B: 0.08

N: 0.13

G: 0.56*
D: 0.56

W: 0.04

H: 0.16

F: 0.86*

Mean number of missing teeth among regularly attending childrenS: 0.36

B: 0.03

N: 0.11

G: 0.58
D: 0.56

W: 0.06

H: 0.11

F: 0.67

Mean number of filled teethS: 0.51

B: 0.29

N: 0.38

G: 0.43**
D: 0.66

W: 0.39

H: 0.43

F: 0.80**

Mean number of filled teeth among regularly attending childrenS: 0.47

B: 0.29

N: 0.45*

G: 0.49*
D: 0.67

W: 0.31

H: 0.31*

F: 0.81*

Percentage with arrested caries on at least one toothS: 20

B: 2

N: 0

G: 4
D: 21

W: 3

H: 1

F: 4

Healthcare costsMean expenditure in GBP per dentist year in participating dental practices during 1988 (percentage change from fee-for service)All: 9430 (31)

S: 10,517 (19)

B: 5185 (-9)

N: 10,030 (35)

G: 10,343 (48)
All: 7193

D: 8870

W: 5708

H: 7417

F: 6976

Mean expenditure in GBP per child in participating dental practices during 1988 (percentage change from fee-for service)

0- to 5-year-oldsAll: 15.98 (41)‡

S: 16.43 (27)

B: 16.83 (58)

N: 15.50 (46)

G: No data
All: ‡

D: 12.97

W: 10.66

H: 10.64

F: No data

6- to 12-year-oldsAll: 23.00 (27)‡

S: 24.99 (20)

B: 22.32 (36)

N: 22.47 (27)

G: No data
All: 18.12‡

D: 20.86

W: 16.39

H: 17.63

F: No data

13- to 15-year-oldsAll: 36.81 (48)‡

S: 36.13 (27)

B: 31.28 (35)

N: 38.00 (58)

G: No data
All:24.94‡

D: 20.55

W: 16.67

H: 17.29

F: No data

0- to 15-year-oldsAll: 22.67 (27)

S: 24.77 (21)

B: 22.85 (37)

N: 24.19 (40)

G: 19.20 (9)
All: 17.90

D: 20.55

W: 16.67

H: 17.29

F: 17.68

Secondary outcomes assessed

Measures of non-clinical behaviour of PCDsProportion of dentists reporting introducing innovations into their dental practices56**69**

Measures of unintended consequences Mean values for temptation expressed by dentists

To over-prescribe16.1**31.0**

To under-prescribe58.3**37.7**

Mean values of clinical freedom expressed by dentists68.2**58.6**

Percentage of principals stating that administration had (over the last three years)

Increased greatly41**10**

Increased slightly42**35**

Percentage of principals stating that bureaucratic intervention had (over the last three years)

Increased or been unchanged70**50**

Decreased30**50**

Percentage of dentists stating views on the accuracy of payments (significance levels are not clearly stated)

Accurate4062

Inaccurate1814

Don't know4224

* P ≤ 0.05

** P ≤ 0.01

Regularly attending children are defined those who had visited the same dentists during the previous year. Using this definition, 70% of the original lists were regular attenders

‡ Only for England

dmft: decayed/missing/filled primary teeth
DMFT: decayed/missing/filled permanent teeth
GBP: Pound Sterling
Health service administrative areas:
B: Bromley; D: Doncaster; F: Fife; G: Grampian; H: Hereford and Worcester; N: Norfolk; S: Salford; W: Wycombe
PCD: primary care dentist



 

Contributions of authors

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

Development of protocol based on the latest Cochrane guidance: Paul Brocklehurst (PRB), Martin Tickle (MT), Stephen Birch (SB), Anne-Marie Glenny (AMG), Beth Mertz (BM) and Jostein Grytten (JG)

Identification of studies: PRB, AMG, Juliet Price (JP)

Data extraction: PRB, AMG, JP

Assessment of risk of bias: PRB, AMG, JP

Data input/synthesis: PRB, AMG, JP

Writing of conclusions: PRB, AMG, JP, BM, MT, SB, JG

 

Declarations of interest

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

There are no financial conflicts of interest and the authors declare that they do not have any associations with any parties who may have vested interests in the results of this review.

 

Sources of support

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms
 

Internal sources

  • School of Dentistry, University of Manchester, UK.

 

External sources

  • No sources of support supplied

 

Differences between protocol and review

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Index terms

Juliet Price joined the review team. We did not undertake an assessment of heterogeneity, reporting bias, data synthesis and subgroup analysis given that there were only two included studies.

* Indicates the major publication for the study

References

References to studies included in this review

  1. Top of page
  2. AbstractRésumé scientifique
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Differences between protocol and review
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. Additional references
Clarkson 2008 {published and unpublished data}
  • Clarkson JE, Turner S, Grimshaw JM, Ramsay CR, Johnston M, Scott A, et al. Changing clinicians' behavior: a randomized controlled trial of fees and education. Journal of Dental Research 2008;87(7):640-4.
Coventry 1989 {published data only (unpublished sought but not used)}
  • Coventry P, Holloway PJ, Lennon MA, Mellor A, Worthington HV. A trial of a capitation system of payment for the treatment of children in the General Dental Service: final report. Community Dental Health 1989;6(Suppl 1):1-63.
  • Holloway PJ, Lennon MA, Mellor AC, Coventry P, Worthington HV. The capitation study. 1. Does capitation encourage "supervised neglect'?. British Dental Journal 1990;168(3):119-21.
  • Lennon MA, Worthington HV, Coventry P, Mellor AC, Holloway PJ. The capitation study. 2. Does capitation encourage more prevention?. British Dental Journal 1990;168(5):213-5.
  • Mellor AC, Coventry P, Worthington HV, Holloway PJ, Lennon MA. The capitation study. 3. The views of participating dentists and the profession. British Dental Journal 1990;168(7):303-5.

References to studies excluded from this review

  1. Top of page
  2. AbstractRésumé scientifique
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Differences between protocol and review
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. Additional references
Blinkhorn 1996 {published data only}
  • Blinkhorn AS, Hassall DC, Holloway PJ, Mellor AC, Worthington HV. An assessment of capitation in the new General Dental Service contract. Community Dental Health 1996;6(Suppl 1):3-20.
Chalkley 2008 {published data only}
  • Chalkley M, Tilley T, Young L, Bonnetti D, Clarkson J. The effect of activity-based payment on dentists' activity: evidence from a natural experiment in the UK National Health Service. www.discovery.dundee.ac.uk/portal/files/105619/DDPE_217.pdf (accessed 3 April 2013).
Fiset 2000 {published data only}
  • Fiset L, Grembowski D, Del Aguila M. Third-party reimbursement and use of fluoride varnish in adults among general dentists in Washington State. Journal of the American Dental Association 2000;131(7):961-8.
Holloway 1997 {published data only}
  • Holloway PJ, Blinkhorn AS, Hassall DC, Mellor AC, Worthington HV. An assessment of capitation in the General Dental Service Contract. 1. The level of caries and its treatment in regularly attending children and adolescents. British Dental Journal 1997;182(11):418-23.
Mayer 2000 {published data only}
  • Mayer ML, Stearns SC, Norton EC, Rozier RG. The effects of Medicaid expansions and reimbursement increases on dentists' participation. Inquiry 2000;37(1):33-44.
Mellor 1994 {published data only}
  • Mellor AC. Resource costs of capitation maintenance care in Britain. Community Dental Health 1994;11(4):188-91.
Mellor 1997 {published data only}
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Additional references

  1. Top of page
  2. AbstractRésumé scientifique
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Differences between protocol and review
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. Additional references
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