Summary of findings
Asthma is the most common chronic disease in childhood, and the high childhood prevalence persists into adulthood (Akinbami 2009; Wenzel 2006), placing a considerable burden on healthcare resources. Thus effective asthma management is important to reduce morbidity and to optimise utilisation of healthcare facilities. This led to the development of (inter)national guidelines for diagnosis and management (GINA 2011; SIGN 2011; de Jongste 2007; Levy 2009). The cornerstone of asthma management is treatment with an inhaled corticosteroid (ICS) (CAMP 2000). Good asthma management is of the utmost importance in achieving control and should include: institution of (inhaled) medication; asthma self-management education including inhaler technique assessment; written asthma plans; self-monitoring of symptoms or airflow, and regular medical review (GINA 2011; Guarnaccia 2007; O'Byrne 2006). Until recently, care was mainly provided by physicians and the role of the asthma nurse supportive in the implementation of these aspects. However, educational interventions, including self-management and self-monitoring by specialised asthma nurses (in nurse-led care) is already widely implemented in many (but not all) general practices and hospitals in high-income countries for more than two decades and have proved to be effective (Gibson 2008 Gibson 2009 Jones 2009; Nathan 2006; Wolf 2008).
The increasing need for asthma management in general and hospital practice emphasises the importance of adequate 'manpower-planning' in primary and secondary care settings (Akinbami 2009). Many general practitioners as well as paediatricians lack sufficient time for such comprehensive care. Several studies suggested that treatment provided in nurse-led care is non-inferior compared to physician-led care (Kamps 2003; Kuethe 2011; Tsai 2005). Furthermore, from a health economic perspective, substitution of workload from physicians to specialised nurses may lead to financial savings. These professionals may be able to work more efficiently than physicians who are often distracted from chronic care tasks by interfering urgent matters.
Taking these factors into account, we formulated the following research question; is nurse-led care in asthma equivalent and not inferior to care delivered by a physician?
Why it is important to do this review
Health economics are increasingly important and intelligent use of human resources is an important issue with regards to effective healthcare. Nurse-led outpatient management may be provided at a lower cost than medical care by a physician. For this reason, is it useful to review the literature in order to find support for the assumption that nurse-led care is not inferior. Until now a systematic literature review on this issue has not been performed.
To review the effectiveness of nurse-led asthma care provided by a specialised asthma nurse, a nurse practitioner, a physician assistant or an otherwise specifically trained nursing professional, working relatively independently from a physician, compared to traditional care provided by a physician. Our scope included all outpatient care for asthma, both in primary care and in hospital settings.
Criteria for considering studies for this review
Types of studies
We included randomised controlled trials (RCTs).
Types of participants
Adults and children with the clinical diagnosis of asthma, as defined by the authors, reviewed on a regular basis in primary or in hospital care. No restrictions were made for co-morbidities.
Types of interventions
Any aspect of asthma management, on a regular basis in primary or hospital care, led by an allied health professional (i.e. specialised asthma nurse, nurse practitioner, physician assistant or an otherwise specifically trained nursing professional), supervised by a physician (nurse-led care).
The same aspect of asthma management provided by a physician.
Types of outcome measures
We assessed effects of interventions on three categories of outcomes where available: patient-related, health economic, and objective measures of lung function, airway reactivity and inflammation.
- Frequency of exacerbations.
- Healthcare costs; direct and indirect.
A. Patient-related variables
- Quality of life: measured by disease specific or generic questionnaires (e.g. Asthma Quality of Life Questionnaire (AQoL) (Juniper 1993).
- Symptom-free days (as measured in symptom diaries).
- Patient satisfaction with care.
- Quality of care, including:
- patient knowledge of asthma and understanding of disease;
- use of an action plan;
- prescription of ICS;
- verifying of appropriate inhalation technique.
- Compliance with medication.
- Use of rescue medication.
- Absence from school or work due to asthma.
- Hospital admissions.
- Referrals from primary to hospital care.
- Duration of consultation and consultations with the specialised asthma nurse, nurse practitioner, physician assistant or an otherwise specifically trained nursing professional and the physician.
- Evidence of stepping down therapy.
C. Objective tests: lung function, airway reactivity, airway inflammation
- Forced expiratory volume in 1 second (FEV
- Peak expiratory flow rate (PEF).
- Airway hyper-reactivity (including PD/PC
20methacholine/histamine (where PD is the provocative dose and PC 20is the concentration inhaled aerosol of methacholine or histamine leading to a fall in FEV 1of 20%)).
Search methods for identification of studies
We identified trials from the Cochrane Airways Group Specialised Register of trials (CAGR), which were derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, AMED and PsycINFO, and handsearching of respiratory journals and meeting abstracts (see Appendix 1 for further details). All records in the CAGR coded as 'asthma' were searched using the following terms: nurse* or nursing* or allied*.
Additional searches of MEDLINE, EMBASE, CINAHL, CENTRAL, AMED and prospective trial registers (the World Health Organization (WHO) trial register and other registers listed in the Cochrane Handbook for Systematic Reviews of Interventions (Section 126.96.36.199; Higgins 2011)) using the keywords: nurse or nursing or allied combined with MeSH terms and free-text words for asthma, combined with the sensitive Cochrane RCT filter were conducted. A search of ClinicalTrials.gov was conducted.
We searched all databases from their inception to August 2012 without restriction to language or status of publication.
Searching other resources
We checked reference lists of all primary studies included in this systematic review and review articles identified by the search strategy for additional references.
Data collection and analysis
Selection of studies
Two review authors (WvA, MCK) independently screened all studies identified by the search strategy on title and abstract for eligibility. Once agreement was obtained on studies to be considered for inclusion, we retrieved full-text articles. Two review authors (WvA, MCK) independently assessed each study for inclusion, based on the pre-defined criteria for study selection. Any disagreement was resolved by discussion.
Data extraction and management
A data extraction form was developed and tested before two review authors (WvA, MCK) independently extracted data from the included studies. MCK entered the data in RevMan 2008. In case of missing data, we attempted to contact authors to confirm data for accuracy and completeness. We extracted the following characteristics:
- Randomisation method.
- Follow-up procedures and withdrawals.
- Sample size.
- Inclusion criteria.
- Exclusion criteria.
- Asthma diagnosis.
- Asthma severity.
- Other medical diagnosis.
- Nurse-led care.
- Physician led care.
- Data on all outcomes as listed in the section Types of outcome measures.
Assessment of risk of bias in included studies
Two review authors (WvA, MCK) independently assessed the risk of bias for each study using the criteria outlined below and judged the risk of bias as high, low or unclear for the criteria listed according to recommendations in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). Since it was not possible to blind nurses, physicians and participating patients in these studies these criteria were all scored as high risk of bias and the potential impact of non-blinding was reflected in the discussion of the results.
The criteria assessed were:
- adequate sequence generation;
- adequate allocation concealment;
- adequate blinding of assessors;
- incomplete outcome data adequately assessed;
- free of suggestion of selective outcome reporting;
- free of other bias.
Measures of treatment effect
We calculated a mean difference (MD) with 95% confidence intervals (CI) for continuous variables measured on identical metrics.
A standardised mean difference (SMD) with 95% CI was used for the same continuous variable measured with different metrics and for dichotomous outcomes, we calculated the risk ratio (RR) and risk difference (RD) with 95% CI.
When incorporating results from cluster randomised studies for continuous and dichotomous variables we extracted direct estimates of effect measures from an analysis that properly accounted for the cluster design and combined results from studies using the generic inverse variance (GIV) method in RevMan 2008.
Dealing with missing data
Investigators or study sponsors were contacted in order to verify key study characteristics and obtain missing numerical outcome data where possible.
Assessment of heterogeneity
We assessed heterogeneity by comparing clinical characteristics of the included studies such as type of patients, intervention, comparison and outcome measures. We discussed clinical homogeneity in the review team. Based on this discussion we decided whether pooling of results was sensible. We initially investigated statistical heterogeneity by visual inspection of the forest plots. We applied the Chi
- 0% to 40%: might not be important;
- 30% to 60%: may represent moderate heterogeneity;
- 50% to 90%: may represent substantial heterogeneity;
- 75% to 100%: considerable heterogeneity.
When interpreting the results of the test for heterogeneity and the I
Assessment of reporting biases
Where we suspected reporting bias, we attempted to contact study authors asking them to provide missing outcome data. Where this was not possible, and the missing data were thought to introduce serious bias, we explored the impact of including such studies in the overall assessment of results using a sensitivity analysis.
We planned to explore publication bias using visual inspection of a funnel plot, if 10 or more studies had been incorporated into a meta-analysis.
If studies were sufficiently comparable in relation to subjects, interventions and outcome variables, we combined data in a meta-analysis. For continuous outcome variables we calculated a weighted MD or a weighted SMD with 95% CI using the GIV method. For dichotomous outcomes, we estimated a pooled RR or RD using the Mantel-Haenszel method. We hypothesised that the individual studies that evaluated the effect of asthma management provided by an allied health professional may contain different, but related, real values per study for the effect; therefore we combined the results using a random-effects model.
Subgroup analysis and investigation of heterogeneity
We planned to carry out the following subgroup analyses:
- adults versus children;
- disease severity (using hospital admissions as a surrogate marker for disease severity);
- doctor-led clinics versus nurse-led clinics versus nurse/doctor shared clinics;
- duration of intervention.
We planned sensitivity analyses to test the robustness of the results based on the risk of bias assessment. We excluded studies according to the following categories: high risk of bias for allocation concealment, high risk of bias for assessor blinding or high risk of bias for incomplete follow-up. If a limited number of studies (≤ four) were included in a meta-analysis, the random-effects model was tested for its robustness using a fixed-effect model. Dichotomous outcomes (RD) were tested for robustness using the Peto odds ratio (OR).
'Summary of findings' table
The quality of the body of evidence was evaluated according to the GRADE system (Higgins 2011), using GRADE pro software (Grade Working Group 2004) to generate a 'Summary of findings' table. We used the most relevant outcomes (number of exacerbations, asthma severity and symptoms, healthcare costs, quality of life, hospital admissions).
Results of RCTs were considered initially as 'high level' evidence. The level of evidence was decreased (downgraded) based on potential risk of bias of the included studies, indirectness of evidence, unexplained heterogeneity or inconsistency in results, imprecision of results or high probability of publication bias (Higgins 2011). The necessity to apply downgrading was evaluated according to previously published criteria (Grade Working Group 2004; Higgins 2011).
Description of studies
Results of the search
The search yielded 360 records; 358 records were found by the search strategy and two studies were identified by handsearching (see Figure 1). Of these records, 154 studies did not address the issue of nurse-led care at all and 181 studies did address the issue of interventions by means of nurse-led care in general but were not related to follow-up. Twenty-five studies were assessed in full text of which five (seven articles) were included.
|Figure 1. Flow diagram.|
The characteristics of included studies are summarised in the Characteristics of included studies table. Five studies (Kamps 2003; Kuethe 2011; Nathan 2006; Pilotto 2004; van Son 2004) were included. The results of two of these studies were each presented in two separate publications (Kamps 2003 and Kuethe 2011).
Two studies were executed in primary care (Pilotto 2004; van Son 2004). One of these studies was performed in two academic primary care centres (van Son 2004). Two studies were executed in general hospitals (Kamps 2003; Nathan 2006) and one study combined primary- and hospital care (Kuethe 2011).
Type of patients
Three studies included adult patients (Nathan 2006; Pilotto 2004; van Son 2004). One of these studies (van Son 2004) also included nurse-led care for patients with another chronic condition (diabetes rather than asthma); however, these patients were analysed separately in a subgroup and therefore we were able to exclude the diabetic patients from our analysis. Two studies included children (Kamps 2003; Kuethe 2011).
Years of publication and countries of origin
All included studies were published after 2000. Three studies originated from the Netherlands (Kamps 2003; Kuethe 2011; van Son 2004). One study (van Son 2004) was published in Dutch. One study was performed in the UK (Nathan 2006) and one study in Australia (Pilotto 2004).
Aspects of intervention
In two studies, the asthma nurse worked strictly according to an algorithm derived from guidelines, whereas the physician in the control group had to work according to same guideline (Kamps 2003; Kuethe 2011). In two studies the intervention group as well as the control group received a similar co-intervention at the beginning of the study (Kamps 2003; Nathan 2006). In the two studies there were co-interventions at the beginning of a follow-up period, without an apparently similar co-intervention in the control group (Pilotto 2004; van Son 2004).
In four studies (Kamps 2003; Kuethe 2011; Pilotto 2004; van Son 2004) the patients had stable asthma and were treated in an outpatient clinic setting in either primary or secondary care. One study included patients who were recently admitted for an asthma exacerbation. These patients were apparently not well controlled (Nathan 2006).
Eighteen studies were excluded after reading the full text and reasons of exclusion are summarised in the Characteristics of excluded studies table. Of these 18 studies, nine did not cover the subject of the review but concerned "added care" to usual care by means of nurse-led care (Alexander 1988; Castro 2003; Catrambone 2000; Charlton 1994; Grieneder 1999; Griffiths 2004; Hughes 1991; Kernick 2002; Levy 2000). Nine studies did compare nurse led care versus physician led care but were either "pre/post" studies (Cave 2001; Charlton 1991; Dickinson 1997; Jones 1995; Lindberg 2002; Weng 2007), were abstracts presented too concise to extract data (Webb 1997) or had co-interventions distracting from our objective or had no clear diagnosis of asthma (Lenz 2004; Mundinger 2000).
Risk of bias in included studies
Most of the included studies were well designed and scored on most items low risk of bias. The results of the risk of bias assessment are summarised in Figure 2 and full details can be found in the Characteristics of included studies tables.
|Figure 2. Risk of bias summary: review authors' judgements about each risk of bias item for each included study.|
One study did not describe the randomisation procedure in detail (van Son 2004) and in one study randomisation per participating centre took place, this procedure was computer generated and statistical analyses were adjusted for clustering (Pilotto 2004). Two studies did not clearly describe allocation concealment (Kamps 2003; van Son 2004). It was unclear whether this resulted in selection bias.
Blinding of participants was not possible as a consequence of the subject involved. None of the studies clearly reported whether the outcome assessor was blinded for allocation. Regarding the objective character of the outcome measures we did not expect a high risk of bias.
Incomplete outcome data
In two studies drop-out was very low and unlikely to lead to attrition bias (Kamps 2003; Kuethe 2011). The reasons for drop-out were described in the text and were not related to the intervention. In two studies there was moderate drop-out or partly incomplete outcomes (Pilotto 2004; van Son 2004). The drop-outs in the intervention group and in the control group were about the same and the reason for drop-out was not described, therefore the risk of attrition bias was scored unclear.
No selective reporting bias was detected, in all studies the pre-defined outcomes were presented.
Other potential sources of bias
No major forms of other bias were found.
Effects of interventions
Primary outcomes: frequency of exacerbations
One study on 154 patients who had recently suffered from an exacerbation were randomised to receive either nurse-led or physician-led care (Nathan 2006). This study reported the number of exacerbations as a primary endpoint. Altogether 98 exacerbations occurred in the nurse-led group and 76 in the physician-led group (rate ratio 1.23; 95% CI 0.91 to 1.66; P = 0.368). Thirty-one patients (45.6%) in the nurse-led group and 32 patients (49.2%) in the physician-led group had one or more exacerbations over the six-month follow-up period. The difference between groups was not statistically significant (OR 0.86; 95% CI 0.44 to 1.71; P = 0.674) (Nathan 2006). The definition for an exacerbation was well described in this study, as a drop in PEF of at least 30% accompanied by increased ICS, emergency nebuliser treatment or a course of oral corticosteroids. In one study in a stable paediatric asthma population (Kuethe 2011), there were no differences between groups regarding the number of exacerbations as expressed by the number of prednisolone courses. In the groups as a whole, few exacerbations occurred (two in general practice group, two in paediatric group and three in nurse-led group). The same applies for the other study in a group of children with stable asthma (Kamps 2003) (median of zero in both groups; P = 0.37); however, no definition of an exacerbation was given. A study in a primary care population (van Son 2004) used exacerbations as the outcome parameter, though they were not well defined in the text. The difference between the intervention and the control groups was also not statistically significant (P = 0.68). It was not possible to pool the data for exacerbations for two reasons. First, in two studies (Kamps 2003; van Son 2004) exacerbations were not defined, and the definitions of exacerbation used in the other two studies (Kuethe 2011; Nathan 2006) were not the same. Second, the raw data (standard deviations (SD)) of these studies could not be retrieved after contacting the authors.
Primary outcomes: asthma severity and symptoms
One study investigated asthma control (Kuethe 2011) making use of the ACQ (Juniper 1999; Juniper 2006). This paediatric study had three arms; general practitioner-led care, paediatrician-led care and asthma nurse-led care. The median ACQ scores after two years in both the general practitioner-led group and the paediatrician-led group did not significantly differ from the nurse-led group (P = 0.18 and 0.28, respectively), demonstrating non-inferiority for the asthma control in the nurse-led group (Kuethe 2011).
Primary outcomes: healthcare costs, direct and indirect
One trial addressed the issue of healthcare costs in nurse- versus physician-led care (Kamps 2003). The costs of outpatient visits was statistically significant lower in the nurse-led group (outpatient visits costs per patient per year; €156 in the nurse-led group versus €189 in the physician-led group; P < 0.001). This difference led to a lower total costs in the healthcare sector, though not statistically significantly (total health costs €343 in nurse led group versus €357 in physician-led group; P = 0.62).
Secondary outcomes: patient-related variables
Quality of life
Three studies had various forms of quality of life scores as outcome parameter. One study (Kamps 2003) used the Dutch version of the Paediatric Asthma Quality of Life Questionnaire (PAQoL) (Juniper 1993; Juniper 1996a; Juniper 1996b). Two studies (Nathan 2006; Pilotto 2004) used the St George's Respiratory Questionnaire (SGRQ; Barley 1998; Jones 1991). In these studies, quality of life improved from baseline over time, but in none of these studies there was a statistically significant difference between the nurse-led groups and the physician-led groups. After meta-analysis no effect was found (SMD -0.03; 95% CI -0.23 to 0.17; Figure 3). Sensitivity analysis using a fixed-effect model yielded the same results (SMD -0.03; 95% CI -0.23 to 0.17). Kamps 2003 also used two other instruments relating to quality of life; the 'Functional health status FS II score' and the 'RAND general health rating index' (Post 1998a; Post 1998b; Stein 1990). The MD in FSII score between the two treatment groups at the end of the study was 10.1 (95% CI -0.3 to 19.8). The MD in RAND score between both groups at the end of the study was 0.1 (95% CI 22.8 to 2.7).
|Figure 3. Forest plot of comparison: 1 Nurse-led versus physician-led, outcome: 1.1 Quality of life at 12 months.|
One study had symptom-free days as the primary outcome parameter (defined as symptom score and use of rescue medication in a diary for the two weeks preceding a follow-up visit) (Kamps 2003). The mean percentage of symptom-free days throughout the study was comparable between the two treatment groups (70.5% in the paediatrician-led group and 68% in the nurse-led group; P = 0.54).
Patient satisfaction with care
One study (van Son 2004) presented data relating to "patient satisfaction with care". However, this study made use of a Dutch scoring system (van Weel 1990) that is derived from an instrument constructed by the "Dartmouth Primary Care Cooperative Project" and is mainly meant to score "ability to perform daily life activities" instead of "patient satisfaction with care" (Nelson 1990).
Quality of care
One study briefly addressed the issue of knowledge of asthma and understanding of disease, but the way of scoring was only vaguely described and seemed to favour nurse-led care (van Son 2004). Two studies in children described explicitly the use of ICS and the prescribed dose (Kamps 2003; Kuethe 2011). In none of these studies did the prescribed dose differ significantly between the nurse-led group and the physician-led group at the end of the study period. The use of an "action plan" and "checking of appropriate inhalation technique" was not presented as an outcome measure in any of the studies.
Kuethe 2011 assessed quality of care and patient satisfaction in a paediatric population with asthma using a revised version of the QUality Of care Through the patient's Eyes-Chronic Non Specific Lung Disease (QUOTE-CNSLD) questionnaire (van Campen 1997), containing a process-, structure- and asthma-specific domain plus a simple five-item child-specific scale; in three arms; general practitioner-led care, paediatrician-led care and nurse-led care. After one year for process and structure quality no statistical differences were found between groups. For asthma-specific and child-specific quality the ratings for the paediatrician-led care and nurse-led were higher than for the general practitioner-led care (P < 0.05).
Compliance with medication
None of the included studies presented data about compliance as an outcome measure.
Use of rescue medication
One study in paediatric patients with stable asthma presented the percentage of "rescue medication free days" (Kamps 2003) without a statistically significant difference at the end of the study period (75.8% in nurse-led group versus 76.8% in physician-led group; P = 0.40).
One study in patients with asthma that was not stable, all older than 16 years, totaled the number of "emergency room nebulization's" and the number of "hospital admissions" in both groups without a statistically significant difference between groups (Nathan 2006). Mean number of exacerbations requiring emergency treatment was 0.59 in nurse-led group versus 0.43 in the physician-led group.
Secondary outcomes: health economics
Absence from school/work due to asthma
Three studies presented data about absence from school or work due to asthma. One study (Kamps 2003) reported a median of zero days school absence in both groups at the end of the study period (median 0 (range 0 to 23) in the nurse-led group, median 0 (range 0 to 21) in the paediatrician-led group (P = 0.80). Another study (Kuethe 2011) also reported no significant difference in school absence between groups. In an adult population. Pilotto and colleagues (Pilotto 2004) reported that 20.6% of patients in the physician-led group had more than one day of absence from work opposed to no patients in the nurse-led group (P = 0.04).
Four studies presented data about hospital (re)admissions (Kamps 2003; Kuethe 2011; Nathan 2006; Pilotto 2004). The pooled data showed substantial heterogeneity (RD -0.02; 95% CI -0.06 to 0.02; I
|Figure 4. Forest plot of comparison: 1 Nurse-led versus physician-led, outcome: 1.2 Hospital admission.|
|Figure 5. Forest plot of comparison: 1 Nurse-led versus physician-led, outcome: 1.4 Hospital admission subgroup analysis.|
Referrals from primary to hospital care
No data presented in any of the included studies.
Duration of consultation and consultations with the asthma nurse and the physician
Kamps and colleagues (Kamps 2003) reported the duration of consultation in the nurse-led group. The mean (SD) duration of the first nurse-led follow-up visit was 29.0 (5.2) minutes. The second and third follow-up visits lasted 19.4 (7.2) and 18.3 (6.3) minutes, respectively. Subsequent nurse-led follow-up visits lasted approximately 15 minutes. No data about duration of consultation were presented for the paediatrician-led group.
One study (Kuethe 2011) reported the extra workload for the physician caused by consultation with the paediatrician by the asthma nurse. In 58% of children the professional providing nurse-led care was confident to provide asthma management without support from the paediatrician. In 34% of the children one or two short oral communications with a paediatrician took place to assist the nurse with management. Eight per cent of the children had problems that required more frequent input from the paediatrician.
Evidence of stepping down therapy
One study (Kamps 2003) presented data about stepping down of ICS. At the end of the study period there were no statistically significant differences. (See also prescription of inhaled corticosteroids under subheading "quality of care").
Objective tests: lung function, airway reactivity, airway inflammation
Forced expiratory volume in 1 second (FEV
|Figure 6. Forest plot of comparison: 1 Nurse-led versus physician-led, outcome: 1.3 FEV|
Peak expiratory flow rate (PEF)
Two studies presented change in peak flow over the course of the study. Nathan and colleagues (Nathan 2006) compared the maximal PEF measurement at first hospital visit with the six-month follow-up measurement. In this study there was a decrease of PEF over time. Mean drop was 2.53% (SD 11.5) in the physician-led group and 3.92% (SD 12.4) in the nurse-led group. No significant difference in change in PEF between the two groups (P = 0.122) was observed. One study (van Son 2004) presented the change in PEF over the study period of one year. In this study there was an increase over time (5.3% in the nurse-led group and 3.94% in the physician-led group), but no statistical significant between group differences were found (P = 0.66).
Airway hyper-reactivity (including PD/PC
One study (Kuethe 2011) presented airway hyper-reactivity as a primary outcome, no statistically significant differences were found between the nurse-led group and the physician-led groups (general practitioner or paediatrician). Another study (Kamps 2003) presented airway hyper-reactivity as log
Summary of main results
The objective was to review the effectiveness of asthma care provided by a specialised asthma nurse, nurse practitioner, physician assistant or an otherwise specifically trained nursing professional, working relatively independently from a physician, compared to traditional care provided by a physician. We found no statistically significant difference between nurse-led care for patients with asthma compared to physician-led care based on the included studies for the outcomes assessed. A small number of parameters favoured nurse-led care over physician-led care, including savings on healthcare costs. Based on the relatively small number of studies in this review, nurse-led care may be appropriate in patients with well-controlled asthma. We included only one study with uncontrolled patients (Nathan 2006). Therefore we cannot be sure whether nurse-led care might be appropriate in patients with uncontrolled asthma.
Overall completeness and applicability of evidence
We did not limit the study search for any language, nevertheless a remarkable proportion of the studies originated from the Netherlands. A probable explanation are the different healthcare settings in different countries. This may limit the extent to which these results may be generalised to countries with different organisation of health care.
This systematic review has some limitations. First, although we had strict selection criteria for inclusion or exclusion (same co-interventions in both groups, active follow-up the same in both groups) it was difficult to apply these criteria on some of the studies. Second, we were not able to perform a funnel plot because of the limited studies included in the review. This makes it difficult to judge whether our findings are biased by publication status. Third, initially we did not include the frequency of consultations with the asthma nurse and the physician in the nurse-led group as an outcome . However, this is an important factor in determining workload for both nurses and physicians. Therefore we decided, post hoc, to add it as an outcome parameter. Fourth, we did not pre-define factors about safety. None of the included studies reported data on adverse events. One study (Kuethe 2011) addressed this issue and proposed a number of prerequisites to be fulfilled: nurse-led care requires working strictly according to guidelines, there should be a low threshold for consulting with a physician when a patient deteriorates or shows unexpected symptoms, and supervision or revision by a physician should always take place when there is uncertainty about the child's management. Finally, a report by Kuethe 2011 presented clear data about quality of care in the three different settings.
Quality of the evidence
The quality of the body of evidence was evaluated according to the GRADE system. For the pooled outcomes moderate level of evidence was found for health-related quality of life and hospital admission. See Summary of findings for the main comparison.
Agreements and disagreements with other studies or reviews
One Cochrane systematic review (Laurant 2005) investigated the efficacy of nurse-led care in primary practice in people with all types of health problems presenting to primary care (excluding accident and emergency departments). They concluded that appropriately trained nurses can produce as high-quality care as primary care doctors. However, their conclusion should be viewed with caution because of different methodological limitations and small sample size of underlying RCTs. One systematic review about the effectiveness of innovations in nurse-led chronic disease management for patients with chronic obstructive pulmonary disease (COPD; Taylor 2005) found little evidence to support the widespread implementation of nurse-led management interventions for COPD, but the data were too sparse to exclude any clinically relevant benefit or harm arising from such interventions. Another review about specialist nurses in diabetes mellitus care (Loveman 2003) concluded in a similar way that the presence of a diabetes specialist nurse/nurse case manager may improve patients' diabetic control over short time periods, but from currently available trials the effects over longer periods of time are not evident. These reviews focused on clinical outcome parameters and did not specifically address the issue of workload reduction for physicians neither the issue of non-inferiority or equivalence of care. In the study concerning healthcare costs (Kamps 2003), the reduction of costs of care in the nurse-led group was surprisingly limited compared to physician-led care. An RCT about healthcare costs of nurse-led care in a bronchiectasis clinic reported that nurse-led care for stable patients within a chronic chest clinic may use more resources (Sharples 2002). In that study, unit cost of the nurse practitioner was under half of that of the consultant. However, patients receiving nurse practitioner led care had more clinic visits per year and, on average, nurse-led clinic visits lasted longer. Combining these factors, almost negated the lower unit cost of the nurse practitioner use indicators.
Implications for practice
No significant difference was found between nurse-led care for patients with asthma compared to physician-led care for outcomes assessed. Based on the relatively small number of studies in this review, nurse-led care may be appropriate in patients with well-controlled asthma. Since only one study with uncontrolled patients was included we cannot be sure whether nurse-led care is appropriate in uncontrolled asthma.
Implications for research
The conclusion of this review is based on a small number of studies. Adverse events should be more precisely addressed in future research. Furthermore research on quality of care in different healthcare settings and in different stadia of asthma control is required. Researchers in the future should incorporate outcome parameters fulfilling the following criteria; 1) well-defined and using validated methods where possible; 2) reported in a manner appropriate for meta-analysis; 3) easy to obtain and 4) relevant for carers of, or people with, asthma and people making decisions around healthcare provision. The primary outcome parameters we choose for this review (frequency of exacerbations, asthma severity and symptoms: measured by validated asthma control questionnaires and healthcare costs; direct and indirect) meet these criteria. Exacerbations, and certainly hospital admissions due to exacerbations, are well definable. For asthma severity, there are a number of very well-validated instruments (Juniper 1999; Juniper 2006; Schatz 2006) which can be easily completed by patients. Financing health care is becoming more and more an issue and therefore the importance costs cannot be overstated. From the societal point of view, the indirect costs in term of loss of labour or loss of school education are as relevant as the direct costs. Although speculative rather than based on the evidence presented in this review, extending nurse-led care seems likely to lead to cost reduction. The issue of costs is even more important in countries where the doctors are scarce and where it may be practically or financially prohibitive to access a physician. Therefore research in this field should be specifically encouraged in developing countries.
Elizabeth Stovold; Trial Search Coordinator, Cochrane Airways Group.
Dr Emma Welsh; Managing Editor, Cochrane Airways Group.
Data and analyses
- Top of page
- Summary of findings [Explanations]
- Authors' conclusions
- Data and analyses
- Contributions of authors
- Declarations of interest
- Sources of support
- Differences between protocol and review
- Index terms
Appendix 1. Sources and search methods for the Cochrane Airways Group Specialised Register (CAGR)
Electronic searches: core databases
Handsearches: core respiratory conference abstracts
MEDLINE search strategy used to identify trials for the CAGR
1. exp Asthma/
3. (antiasthma$ or anti-asthma$).mp.
4. Respiratory Sounds/
6. Bronchial Spasm/
8. (bronch$ adj3 spasm$).mp.
10. exp Bronchoconstriction/
11. (bronch$ adj3 constrict$).mp.
12. Bronchial Hyperreactivity/
13. Respiratory Hypersensitivity/
14. ((bronchial$ or respiratory or airway$ or lung$) adj3 (hypersensitiv$ or hyperreactiv$ or allerg$ or insufficiency)).mp.
15. ((dust or mite$) adj3 (allerg$ or hypersensitiv$)).mp.
Filter to identify RCTs
1. exp "clinical trial [publication type]"/
2. (randomised or randomised).ab,ti.
11. 9 not (9 and 10)
12. 8 not 11
The MEDLINE strategy and RCT filter are adapted to identify trials in other electronic databases
Contributions of authors
- Designing of draft (RE, MCK).
- Conceptualisation (MCK, WvA, AVV, RE).
- Writing Draft (MCK).
- Reviewing draft (RE, AVV, WvA).
- Reviewing (WvA, MCK).
- Third assessor (AVV).
Declarations of interest
- None known.
Sources of support
- New Source of support, Not specified.
- No sources of support supplied
Differences between protocol and review
The search has been amended.
Medical Subject Headings (MeSH)
MeSH check words
Adult; Child; Humans
* Indicates the major publication for the study