Interventions for increasing solid organ donor registration

  • Protocol
  • Intervention

Authors


Abstract

This is the protocol for a review and there is no abstract. The objectives are as follows:

This review aims to look at the benefits and harms of various interventions used to increase deceased organ donor registration.

Background

Description of the condition

Many patients worldwide are dying on the transplant waiting list due to the shortage of available organs (Aubrey 2008; Santiago-Delpin 1997; Van Gelder 2008; Wolfe 2010). One potential solution for increasing the number of available organs for transplantation is to increase the number of individuals registering a commitment for deceased organ donation through a registry (Rosenblum 2012). Despite support from the public and national organisations for donor registries, many countries have modest registration rates (< 40% of the population registered) (Rosenblum 2012).

Description of the intervention

Nineteen countries operate deceased organ donor registries where the stated goal is to maximise the total number of affirmative registrants (Rosenblum 2012). These registries are used to communicate an individual’s wish regarding organ donation after death to their next-of-kin. Registration choices differ among nations. Registration choices can include “yes” only, “yes and no” and “yes, no and unsure”. Studies have found that families are more likely to consent to organ donation if their loved ones had previously expressed a willingness to donate (e.g. on a donor card or driver’s licence) (Lawlor 2006; Siminoff 2002).

How the intervention might work

Many interventions can effectively increase knowledge, attitude, and prompt family discussion about organ donation (Li 2013). These interventions can include mass media campaigns and classroom educational programs. Such interventions have been shown to benefit other public health issues such as drink-driving (Elder 2004) and smoking (Bala 2013). However, few interventions have actually demonstrated an increase in the number of individuals registering a commitment to organ donation (Li 2013; Thornton 2012). Surveys have further found that a majority of respondents were willing to be donors, but many had not registered (Lee 2010; Yeung 2000). The gap between willingness to be a donor and actual registration may be due to lack of awareness of the registry, the registration process, or fear of placing their name in a large database (Siegel 2005; Yeung 2000).

Why it is important to do this review

The need for interventions to demonstrate effectiveness beyond support for organ donation to actual affirmative registration values prompted the current study. This systematic review will synthesize the best evidence currently available from studies evaluating various interventions to increase affirmative organ donor registrants. This review aims to guide the design and use of further interventions to fill organ donor registries. The focus of this review is on solid organ donations after death. Interventions may benefit society if an increased number of organ donor registrants translate to an increased number of deceased donors. However, these interventions may also be detrimental to society or individual participants if they unintentionally discourage deceased organ donation.

Objectives

This review aims to look at the benefits and harms of various interventions used to increase deceased organ donor registration.

Methods

Criteria for considering studies for this review

Types of studies

We will include all randomised controlled trials (RCTs), quasi-RCTs (RCTs in which allocation to treatment was obtained by alternation, use of alternate medical records, date of birth or other predictable methods), cluster RCTs and controlled before-after studies evaluating interventions for increasing donor registration. Controlled before-after studies are eligible for inclusion if donor registration status, self-reported intention or willingness to become an organ donor was measured in both intervention and control groups before and after the introduction of the intervention. These studies are included because it may be difficult to randomise participants in certain settings such as the workplace or schools where educational interventions may have been implemented. We will exclude studies from countries that do not comply with the Declaration of Istanbul.

Types of participants

Inclusion criteria

All participants eligible to register for deceased organ donation.

Exclusion criteria

Participants who are not eligible to register for deceased organ donation in their respective jurisdiction (e.g. under the minimum age required).

We will exclude studies that examined consent for organ donation from relatives of patients declared deceased and eligible for organ donation. We will also exclude studies focusing on increasing living organ donation.

Types of interventions

We will consider any interventions used to increase organ donor registration including classroom educational programs, brochures, interactive computer programs, videos and multi-component interventions. The comparison group can be an inactive control intervention (e.g. no intervention) or an active intervention (e.g. different variant of an educational program).

We will exclude interventions solely focusing on tissue or blood donation.

Types of outcome measures

The properties for joining an organ donor registry vary among countries. We will include studies that measure consent to deceased organ donation through registration in an organ donor registry, signed donor cards or verification of organ donation registration as shown on a driver’s licence or identification card. For this reason, we expect that all interventions come from countries with an explicit consent or "opt-in" system. Registration choices may also be measured and may include "yes" (the participant declares that they would like to be a deceased organ donor in the advent of death), "no" and "unsure". We will also include studies that measured self-reported intention or willingness to become an organ donor. We will also extract any adverse events reported in any studies. Adverse events may include discomfort or dissatisfaction with the intervention.

Primary outcomes
  1. Registration in an organ donor registry (yes/no) and registration choices ("yes" to being a donor, "no" or "unsure")

  2. Signed donor cards (yes/no)

  3. Verification of organ donation as shown on driver's licence or identification card (yes/no)

  4. Any adverse events. (e.g. discomfort with the intervention)

Secondary outcomes
  1. Self-reported intention to register as a donor (e.g. Do you intend to register as a donor?)

  2. Self-reported willingness to donation (e.g. Would you be willing to donate your organs?)

These can be either reported as yes/no or on a scale (e.g. yes/no/maybe, fully agree to fully disagree).

Search methods for identification of studies

Electronic searches

We will search the Cochrane Renal Group's Specialised Register through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

The Cochrane Renal Group’s Specialised Register contains studies identified from:

  1. Monthly searches of the Cochrane Central Register of Controlled Trials (CENTRAL)

  2. Weekly searches of MEDLINE OVID SP

  3. Handsearching of renal-related journals and the proceedings of major renal conferences

  4. Searching of the current year of EMBASE OVID SP

  5. Weekly current awareness alerts for selected renal journals

  6. Searches of the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

Studies contained in the Specialised Register are identified through search strategies for CENTRAL, MEDLINE, and EMBASE based on the scope of the Cochrane Renal Group. Details of these strategies, as well as a list of handsearched journals, conference proceedings and current awareness alerts, are available in the Specialised Register section of information about the Cochrane Renal Group. See Appendix 1 for search terms used in strategies for this review.

CINAHL will be searched using the terms in Appendix 1.

Searching other resources

  1. Reference lists of clinical practice guidelines, review articles and relevant studies.

  2. Letters seeking information about unpublished or incomplete studies to investigators known to be involved in previous studies.

Data collection and analysis

Selection of studies

The search strategy described will be used to obtain titles and abstracts of studies that may be relevant to the review. The titles and abstracts will be screened independently by two authors, who will discard studies that are not applicable; however studies and reviews that might include relevant data or information on studies will be retained initially. Two authors will independently assess retrieved abstracts and, if necessary the full text, of these studies to determine which studies satisfy the inclusion criteria.

Data extraction and management

Data extraction will be carried out independently by two authors using standard data extraction forms. Where more than one publication of one study exists, reports will be grouped together and the publication with the most complete data will be used in the analyses. Where relevant outcomes are only published in earlier versions these data will be used. Any discrepancy between published versions will be highlighted. For each study, we will extract relevant background information to provide context regarding its country's organ donor legislation.

Assessment of risk of bias in included studies

The following items will be independently assessed by two authors using the risk of bias assessment tool (Higgins 2011) (see Appendix 2). The risk of bias in the before-after studies will also be examined using the same tool.

  • Was there adequate sequence generation (selection bias)?

  • Was allocation adequately concealed (selection bias)?

  • Was knowledge of the allocated interventions adequately prevented during the study (detection bias)?

    • Participants and personnel

    • Outcome assessors

  • Were incomplete outcome data adequately addressed (attrition bias)?

  • Are reports of the study free of suggestion of selective outcome reporting (reporting bias)?

  • Was the study apparently free of other problems that could put it at a risk of bias?

Measures of treatment effect

For dichotomous outcomes (e.g. donor registration status (yes/no)) results will be expressed as risk ratio (RR) with 95% confidence intervals (CI). Where continuous scales of measurement are used to assess the effects of treatment (e.g. a scale of willingness to register as a donor), the mean difference (MD) will be used, or the standardised mean difference (SMD) if different scales have been used.

Unit of analysis issues

We will handle issues with non-standard designs such as cluster-RCTs as recommended by the Cochrane Handbook for Systematic Interventions (Higgins 2011). We will estimate the effective sample size by dividing the original sample size by the design effect (1 + (Average Cluster Size -1) * Intra-cluster correlation coefficient). We will contact the authors to obtain the intra-class correlation coefficients of their clustered data if needed. If authors cannot be reached, we will use intra-class correlation estimates based on previous studies. For dichotomous outcomes, both numbers of participants and numbers of participants registered for organ donation will be divided by the design effect.

Dealing with missing data

Any further information required from the original author will be requested by written correspondence (e.g. emailing or writing to corresponding author) and any relevant information obtained in this manner will be included in the review. Evaluation of important numerical data such as screened, randomised patients as well as intention-to-treat, as-treated and per-protocol population will be carefully performed. Attrition rates, for example drop-outs, losses to follow-up and withdrawals will be investigated. Issues of missing data and imputation methods (e.g. last-observation-carried-forward) will be critically appraised (Higgins 2011).

Assessment of heterogeneity

Heterogeneity will be analysed using a Chi² test on N-1 degrees of freedom, with an alpha of 0.05 used for statistical significance and with the I² test (Higgins 2003). I² values of 25%, 50% and 75% correspond to low, medium and high levels of heterogeneity.

Assessment of reporting biases

If possible, funnel plots will be used to assess for the potential existence of small study bias (Higgins 2011).

Data synthesis

Data will be pooled using the random-effects model but the fixed-effect model will also be used to ensure robustness of the model chosen and susceptibility to outliers.

Subgroup analysis and investigation of heterogeneity

Subgroup analysis will be used to explore possible sources of heterogeneity (e.g. participants, interventions and study quality). Heterogeneity among participants could be related to age, gender, educational level or ethnicity. Heterogeneity in organ donor interventions may be related to the personnel delivering the intervention (e.g. volunteers, health care workers or transplant recipients), duration and type of intervention (e.g. educational programs, videos). Adverse effects will be tabulated and assessed with descriptive techniques, as they are likely to be different for the various interventions used. Where possible, the risk difference with 95% CI will be calculated for each adverse effect, either compared to no intervention or to another intervention. Adverse events may include discomfort or dissatisfaction with the intervention.

Sensitivity analysis

We will perform sensitivity analyses in order to explore the influence of the following factors on effect size.

  • Repeating the analysis excluding unpublished studies

  • Repeating the analysis taking account of risk of bias

  • Repeating the analysis excluding any very long or large studies to establish how much they dominate the results

  • Repeating the analysis excluding studies using the following filters: diagnostic criteria, language of publication, source of funding (industry versus other), and country.

Acknowledgements

We wish to thank the referees for their comments and feedback during the preparation of this protocol.

Mr Li was supported by a Kidney Foundation Scholarship. Ms Naylor was supported by Osteoporosis Canada’s Canadian Multicentre Osteoporosis Study (CaMos) Fellowship. Dr Garg was supported by a CIHR Clinician-Scientist Award.

Appendices

Appendix 1. Electronic search strategies

DatabaseSearch terms
CENTRAL
  1. MeSH descriptor: [Tissue and Organ Procurement] this term only

  2. ((tissue or organ or organs) next donor*):ti,ab,kw

  3. ((tissue or organ or organs) near donat*):ti,ab,kw

  4. (deceased next donor*):ti,ab,kw

  5. {or #1-#4}

  6. (register or registers):ti,ab,kw

  7. (registry or registries):ti,ab,kw

  8. registrant*:ti,ab,kw

  9. registration:ti,ab,kw

  10. "Attitude to health":kw

  11. ((willingness or intention or opinion or opinions or attitude*) near (donat* or donor*)):ti,ab

  12. (donor designation):ti,ab,kw

  13. {or #6-#12}

  14. {and #5, #13}

MEDLINE
  1. Tissue Donors/

  2. "Tissue and Organ Procurement"/

  3. Organ Transplantation/

  4. (organ donor* or tissue donor*).tw.

  5. ((organ or organs or tissue) adj3 donat*).tw.

  6. deceased donor*.tw.

  7. or/1-6

  8. Registries/

  9. (register or registers).tw.

  10. (registry or registries).tw.

  11. registrant*.tw.

  12. registration.tw.

  13. "Attitude to Health"/

  14. ((willingness or intention or opinion or opinions or attitude*) adj10 (donat* or donor*)).tw.

  15. donor designation.tw.

  16. or/8-15

  17. and/7,16

EMBASE
  1. organ donor/

  2. directed tissue donation/

  3. organ transplantation/

  4. (organ donor* or tissue donor*).tw.

  5. ((organ or organs or tissue) adj3 donat*).tw.

  6. deceased donor*.tw.

  7. or/1-6

  8. registry/

  9. registration/

  10. (register or registers).tw.

  11. (registry or registries).tw.

  12. registrant*.tw.

  13. registration.tw.

  14. "attitude to health"/

  15. ((willingness or intention or opinion or opinions or attitude*) adj10 (donat* or donor*)).tw.

  16. donor designation.tw.

  17. or/8-16

  18. and/7,17

CINAHL
  1. (MH "Tissue and Organ Harvesting+") 

  2. (MH "Living Donors") 

  3. (MH "Organ Transplantation+")

  4. (MH "Organ Procurement+")

  5. TI organ donor*

  6. AB organ donor* 

  7. TI tissue donor* 

  8. AB tissue donor* 

  9. TI deceased donor* 

  10. AB deceased donor* 

  11. (MH "Organ Procurement+") 

  12. OR/1-11

  13. (MM "Organ Donor Cards") 

  14. TI register* 

  15. AB register* 

  16. TI registry 

  17. AB registry 

  18. TI registries 

  19. AB registries 

  20. TI registrant* 

  21. AB registrant* 

  22. TI registration* 

  23. AB registration* 

  24. (MM "Health Beliefs") 

  25. (MM "Attitude to Health") 

  26. TI donor designation 

  27. AB donor designation 

  28. willingness N5 (donor* or donat*) 

  29. intention N5 (donor* or donat*) 

  30. attitude N5 (donor* or donat*) 

  31. opinion* N5 (donor* or donat*)

  32. OR/13-31

  33. AND/12,32

Appendix 2. Risk of bias assessment tool

Potential source of bias Assessment criteria

Random sequence generation

Selection bias (biased allocation to interventions) due to inadequate generation of a randomised sequence

Low risk of bias: Random number table; computer random number generator; coin tossing; shuffling cards or envelopes; throwing dice; drawing of lots; minimization (minimization may be implemented without a random element, and this is considered to be equivalent to being random).
High risk of bias: Sequence generated by odd or even date of birth; date (or day) of admission; sequence generated by hospital or clinic record number; allocation by judgement of the clinician; by preference of the participant; based on the results of a laboratory test or a series of tests; by availability of the intervention.
Unclear: Insufficient information about the sequence generation process to permit judgement.

Allocation concealment

Selection bias (biased allocation to interventions) due to inadequate concealment of allocations prior to assignment

Low risk of bias: Randomisation method described that would not allow investigator/participant to know or influence intervention group before eligible participant entered in the study (e.g. central allocation, including telephone, web-based, and pharmacy-controlled, randomisation; sequentially numbered drug containers of identical appearance; sequentially numbered, opaque, sealed envelopes).
High risk of bias: Using an open random allocation schedule (e.g. a list of random numbers); assignment envelopes were used without appropriate safeguards (e.g. if envelopes were unsealed or non-opaque or not sequentially numbered); alternation or rotation; date of birth; case record number; any other explicitly unconcealed procedure.
Unclear: Randomisation stated but no information on method used is available.

Blinding of participants and personnel

Performance bias due to knowledge of the allocated interventions by participants and personnel during the study

Low risk of bias: No blinding or incomplete blinding, but the review authors judge that the outcome is not likely to be influenced by lack of blinding; blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken.
High risk of bias: No blinding or incomplete blinding, and the outcome is likely to be influenced by lack of blinding; blinding of key study participants and personnel attempted, but likely that the blinding could have been broken, and the outcome is likely to be influenced by lack of blinding.
Unclear: Insufficient information to permit judgement

Blinding of outcome assessment

Detection bias due to knowledge of the allocated interventions by outcome assessors.

Low risk of bias: No blinding of outcome assessment, but the review authors judge that the outcome measurement is not likely to be influenced by lack of blinding; blinding of outcome assessment ensured, and unlikely that the blinding could have been broken.
High risk of bias: No blinding of outcome assessment, and the outcome measurement is likely to be influenced by lack of blinding; blinding of outcome assessment, but likely that the blinding could have been broken, and the outcome measurement is likely to be influenced by lack of blinding.
Unclear: Insufficient information to permit judgement

Incomplete outcome data

Attrition bias due to amount, nature or handling of incomplete outcome data.

Low risk of bias: No missing outcome data; reasons for missing outcome data unlikely to be related to true outcome (for survival data, censoring unlikely to be introducing bias); missing outcome data balanced in numbers across intervention groups, with similar reasons for missing data across groups; for dichotomous outcome data, the proportion of missing outcomes compared with observed event risk not enough to have a clinically relevant impact on the intervention effect estimate; for continuous outcome data, plausible effect size (difference in means or standardized difference in means) among missing outcomes not enough to have a clinically relevant impact on observed effect size; missing data have been imputed using appropriate methods.
High risk of bias: Reason for missing outcome data likely to be related to true outcome, with either imbalance in numbers or reasons for missing data across intervention groups; for dichotomous outcome data, the proportion of missing outcomes compared with observed event risk enough to induce clinically relevant bias in intervention effect estimate; for continuous outcome data, plausible effect size (difference in means or standardized difference in means) among missing outcomes enough to induce clinically relevant bias in observed effect size; ‘as-treated’ analysis done with substantial departure of the intervention received from that assigned at randomisation; potentially inappropriate application of simple imputation.
Unclear: Insufficient information to permit judgement

Selective reporting

Reporting bias due to selective outcome reporting

Low risk of bias: The study protocol is available and all of the study’s pre-specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre-specified way; the study protocol is not available but it is clear that the published reports include all expected outcomes, including those that were pre-specified (convincing text of this nature may be uncommon).
High risk of bias: Not all of the study’s pre-specified primary outcomes have been reported; one or more primary outcomes is reported using measurements, analysis methods or subsets of the data (e.g. subscales) that were not pre-specified; one or more reported primary outcomes were not pre-specified (unless clear justification for their reporting is provided, such as an unexpected adverse effect); one or more outcomes of interest in the review are reported incompletely so that they cannot be entered in a meta-analysis; the study report fails to include results for a key outcome that would be expected to have been reported for such a study.
Unclear: Insufficient information to permit judgement

Other bias

Bias due to problems not covered elsewhere in the table

Low risk of bias: The study appears to be free of other sources of bias.
High risk of bias: Had a potential source of bias related to the specific study design used; stopped early due to some data-dependent process (including a formal-stopping rule); had extreme baseline imbalance; has been claimed to have been fraudulent; had some other problem.
Unclear: Insufficient information to assess whether an important risk of bias exists; insufficient rationale or evidence that an identified problem will introduce bias.

Contributions of authors

  1. Draft the protocol: AHL, KLN

  2. Study selection: AHL, KLN

  3. Extract data from studies: AHL, KLN

  4. Enter data into RevMan: AHL, KLN

  5. Carry out the analysis: AHL, KLN, AXG

  6. Interpret the analysis: AHL, KLN, AXG

  7. Draft the final review: AHL KLN, AXG

  8. Disagreement resolution: AXG

  9. Update the review: AHL

Declarations of interest

None known.

Sources of support

Internal sources

  • Nil, Not specified.

External sources

  • No sources of support supplied

Ancillary