Ethical and policy issues in cluster randomized trials: rationale and design of a mixed methods research study

Prevention of Infections in Cardiac Surgery study (PICS): study protocol for a pragmatic cluster-randomized factorial crossover pilot trial

Background

A wide range of prophylactic antibiotic regimens are used for patients undergoing open-heart cardiac surgery. This reflects clinical equipoise in choice and duration of antibiotic agents. Although individual-level randomized control trials (RCT) are considered the gold standard when evaluating the efficacy of an intervention, this approach is highly resource intensive and a cluster RCT can be more appropriate for testing clinical effectiveness in a real-world setting.

Methods/design

We are conducting a factorial cluster-randomized crossover pilot trial in cardiac surgery patients to evaluate the feasibility of this design for a definite trial to evaluate the optimal duration and choice of perioperative antibiotic prophylaxis. Specifically, we will evaluate: (a) the non-inferiority of a single preoperative dose compared to prolonged prophylaxis and (b) the potential superiority of adding vancomycin to routine cefazolin in terms of preventing deep and organ/space sternal surgical site infections (s-SSIs). There are four strategies: (i) short-term cefazolin, (ii) long-term cefazolin, (iii) short-term cefazolin + vancomycin, and (iv) long-term cefazolin + vancomycin. These strategies are delivered in a different order in each health-care center participating in the trial. The centers are randomized to an order, and the current strategy becomes the standard operating procedure in that center during the study.

The three feasibility outcomes include: (1) the proportion of patients receiving preoperative, intra-operative, and postoperative antibiotics according to the study protocol, (2) the proportion of completed follow-up assessments, and (3) a full and final assessment of the incidence of s-SSIs by the outcome adjudication committee.

Discussion

We believe that a cluster-randomized factorial crossover trial is an effective and feasible design for these research questions, allowing an evaluation of the clinical effectiveness in a real-world setting. A waiver of individual informed consent was considered appropriate by the research ethics boards in each participating site in Canada as long as an information letter with an opt-out option was provided. However, a waiver of consent was not approved at two sites in Germany and Switzerland, respectively.

Trial registration

Clinicaltrials.gov, NCT02285140. Registered on 15 October 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3080-y) contains supplementary material, which is available to authorized users.

Developing a framework for the ethical design and conduct of pragmatic trials in healthcare: a mixed methods research protocol

Background

There is a widely recognized need for more pragmatic trials that evaluate interventions in real-world settings to inform decision-making by patients, providers, and health system leaders. Increasing availability of electronic health records, centralized research ethics review, and novel trial designs, combined with support and resources from governments worldwide for patient-centered research, have created an unprecedented opportunity to advance the conduct of pragmatic trials, which can ultimately improve patient health and health system outcomes. Such trials raise ethical issues that have not yet been fully addressed, with existing literature concentrating on regulations in specific jurisdictions rather than arguments grounded in ethical principles. Proposed solutions (e.g. using different regulations in “learning healthcare systems”) are speculative with no guarantee of improvement over existing oversight procedures. Most importantly, the literature does not reflect a broad vision of protecting the core liberty and welfare interests of research participants. Novel ethical guidance is required. We have assembled a team of ethicists, trialists, methodologists, social scientists, knowledge users, and community members with the goal of developing guidance for the ethical design and conduct of pragmatic trials.

Methods

Our project will combine empirical and conceptual work and a consensus development process. Empirical work will: (1) identify a comprehensive list of ethical issues through interviews with a small group of key informants (e.g. trialists, ethicists, chairs of research ethics committees); (2) document current practices by reviewing a random sample of pragmatic trials and surveying authors; (3) elicit views of chairs of research ethics committees through surveys in Canada, UK, USA, France, and Australia; and (4) elicit views and experiences of community members and health system leaders through focus groups and surveys. Conceptual work will consist of an ethical analysis of identified issues and the development of new ethical solutions, outlining principles, policy options, and rationales. The consensus development process will involve an independent expert panel to develop a final guidance document.

Discussion

Planned output includes manuscripts, educational materials, and tailored guidance documents to inform and support researchers, research ethics committees, journal editors, regulators, and funders in the ethical design and conduct of pragmatic trials.

Methodological issues in the design and evaluation of supported communication for aphasia training: a cluster-controlled feasibility study

OBJECTIVE

To assess the feasibility and acceptability of training stroke service staff to provide supported communication for people with moderate-severe aphasia in the acute phase; assess the suitability of outcome measures; collect data to inform sample size and Health Economic evaluation in a definitive trial.

DESIGN

Phase II cluster-controlled, observer-blinded feasibility study.

SETTINGS

In-patient stroke rehabilitation units in the UK matched for bed numbers and staffing were assigned to control and intervention conditions.

PARTICIPANTS

70 stroke rehabilitation staff from all professional groups, excluding doctors, were recruited. 20 patients with moderate-severe aphasia were recruited.

INTERVENTION

Supported communication for aphasia training, adapted to the stroke unit context versus usual care. Training was supplemented by a staff learning log, refresher sessions and provision of communication resources.

MAIN OUTCOME MEASURES

Feasibility of recruitment and acceptability of the intervention and of measures required to assess outcomes and Health Economic evaluation in a definitive trial. Staff outcomes: Measure of Support in Conversation; patient outcomes: Stroke and Aphasia Quality of Life Scale; Communicative Access Measure for Stroke; Therapy Outcome Measures for aphasia; EQ-5D-3L was used to assess health outcomes.

RESULTS

Feasibility of staff recruitment was demonstrated. Training in the intervention was carried out with 28 staff and was found to be acceptable in qualitative reports. 20 patients consented to take part, 6 withdrew. 18 underwent all measures at baseline; 16 at discharge; and 14 at 6-month follow-up. Of 175 patients screened 71% were deemed to be ineligible, either lacking capacity or too unwell to participate. Poor completion rates impacted on assessment of patient outcomes. We were able to collect sufficient data at baseline, discharge and follow-up for economic evaluation.

CONCLUSIONS

The feasibility study informed components of the intervention and implementation in day-to-day practice. Modifications to the design are needed before a definitive cluster-randomised trial can be undertaken.

TRIAL REGISTRATION NUMBER

ISRCTN37002304; Results.

Cluster-randomized trials: A closer look

BACKGROUND

The cluster-randomized trial is the methodology of choice for evaluating interventions administered at the group level such as public health and healthcare quality improvement interventions. Because of unique features of this design, it can be difficult to apply standard research ethics guidelines to cluster-randomized trials. The Ottawa Statement on the Ethical Design and Conduct of Cluster-Randomized Trials provides researchers and research ethics committees with comprehensive guidance on the ethical design, conduct and review of cluster-randomized trials. The Ottawa Statement supplements current national and international research ethics guidelines with guidance that is specific to cluster-randomized trials. In a recently published commentary, three examples drawn from the ClinicalTrials.gov registry were used to illustrate challenges associated with the cluster-randomized trial design. The commentary argued that the Ottawa Statement fails to provide comprehensive ethical guidance. In this article, we illustrate the application of the Ottawa Statement to the three trials. We challenge the conclusions reached in the commentary by demonstrating that an ethical analysis requires complete information. We correct some misperceptions about the cluster-randomized trial design.

METHODS

We collected essential additional information by contacting the authors of trials and by referring to published trial articles. We used the Ottawa Statement to conduct an ethical analysis of each trial and to address a number of substantive concerns raised regarding the identification of study participants, informed consent and harm benefit analysis.

RESULTS

In the two cases in which we were able to obtain detailed study information, we were able to complete the ethical analysis prescribed by the Ottawa Statement.

CONCLUSION

The Ottawa Statement does provide a useful framework for the ethical design, review and conduct of cluster-randomized trials.

Mail merge can be used to create personalized questionnaires in complex surveys

Background

Low response rates and inadequate question comprehension threaten the validity of survey results. We describe a simple procedure to implement personalized—as opposed to generically worded—questionnaires in the context of a complex web-based survey of corresponding authors of a random sample of 300 published cluster randomized trials. The purpose of the survey was to gather more detailed information about informed consent procedures used in the trial, over and above basic information provided in the trial report. We describe our approach—which allowed extensive personalization without the need for specialized computer technology—and discuss its potential application in similar settings.

Results

The mail merge feature of standard word processing software was used to generate unique, personalized questionnaires for each author by incorporating specific information from the article, including naming the randomization unit (e.g., family practice, school, worksite), and identifying specific individuals who may have been considered research participants at the cluster level (family doctors, teachers, employers) and individual level (patients, students, employees) in questions regarding informed consent procedures in the trial. The response rate was relatively high (64 %, 182/285) and did not vary significantly by author, publication, or study characteristics. The refusal rate was low (7 %).

Conclusion

While controlled studies are required to examine the specific effects of our approach on comprehension, quality of responses, and response rates, we showed how mail merge can be used as a simple but useful tool to add personalized fields to complex survey questionnaires, or to request additional information required from study authors. One potential application is in eliciting specific information about published articles from study authors when conducting systematic reviews and meta-analyses.

Challenges of cluster randomized trials

Cluster randomized trials are trials that randomize clusters of people, rather than individuals. They are becoming increasingly common. A number of innovations have been developed recently, particularly in the calculation of the required size of a cluster trial, the handling of missing data, designs to minimize recruitment bias, the ethics of cluster randomized trials and the stepped wedge design. This article will highlight and illustrate these developments. It will also discuss issues with regards to the reporting of cluster randomized trials.

A mixed-methods study on perceptions towards use of Rapid Ethical Assessment to improve informed consent processes for health research in a low-income setting

Background

Rapid Ethical Assessment (REA) is a form of rapid ethnographic assessment conducted at the beginning of research project to guide the consent process with the objective of reconciling universal ethical guidance with specific research contexts. The current study is conducted to assess the perceived relevance of introducing REA as a mainstream tool in Ethiopia.

Methods

Mixed methods research using a sequential explanatory approach was conducted from July to September 2012, including 241 cross-sectional, self-administered and 19 qualitative, in-depth interviews among health researchers and regulators including ethics committee members in Ethiopian health research institutions and universities.

Results

In their evaluation of the consent process, only 40.2% thought that the consent process and information given were adequately understood by study participants; 84.6% claimed they were not satisfied with the current consent process and 85.5% thought the best interests of study participants were not adequately considered. Commonly mentioned consent-related problems included lack of clarity (48.1%), inadequate information (34%), language barriers (28.2%), cultural differences (27.4%), undue expectations (26.6%) and power imbalances (20.7%). About 95.4% believed that consent should be contextualized to the study setting and 39.4% thought REA would be an appropriate approach to improve the perceived problems. Qualitative findings helped to further explore the gaps identified in the quantitative findings and to map-out concerns related to the current research consent process in Ethiopia. Suggestions included, conducting REA during the pre-test (pilot) phase of studies when applicable. The need for clear guidance for researchers on issues such as when and how to apply the REA tools was stressed.

Conclusion

The study findings clearly indicated that there are perceived to be correctable gaps in the consent process of medical research in Ethiopia. REA is considered relevant by researchers and stakeholders to address these gaps. Exploring further the feasibility and applicability of REA is recommended.

Variability in research ethics review of cluster randomized trials: a scenario-based survey in three countries

Background

Cluster randomized trials (CRTs) present unique ethical challenges. In the absence of a uniform standard for their ethical design and conduct, problems such as variability in procedures and requirements by different research ethics committees will persist. We aimed to assess the need for ethics guidelines for CRTs among research ethics chairs internationally, investigate variability in procedures for research ethics review of CRTs within and among countries, and elicit research ethics chairs’ perspectives on specific ethical issues in CRTs, including the identification of research subjects. The proper identification of research subjects is a necessary requirement in the research ethics review process, to help ensure, on the one hand, that subjects are protected from harm and exploitation, and on the other, that reviews of CRTs are completed efficiently.

Methods

A web-based survey with closed- and open-ended questions was administered to research ethics chairs in Canada, the United States, and the United Kingdom. The survey presented three scenarios of CRTs involving cluster-level, professional-level, and individual-level interventions. For each scenario, a series of questions was posed with respect to the type of review required (full, expedited, or no review) and the identification of research subjects at cluster and individual levels.

Results

A total of 189 (35%) of 542 chairs responded. Overall, 144 (84%, 95% CI 79 to 90%) agreed or strongly agreed that there is a need for ethics guidelines for CRTs and 158 (92%, 95% CI 88 to 96%) agreed or strongly agreed that research ethics committees could be better informed about distinct ethical issues surrounding CRTs. There was considerable variability among research ethics chairs with respect to the type of review required, as well as the identification of research subjects. The cluster-cluster and professional-cluster scenarios produced the most disagreement.

Conclusions

Research ethics committees identified a clear need for ethics guidelines for CRTs and education about distinct ethical issues in CRTs. There is disagreement among committees, even within the same countries, with respect to key questions in the ethics review of CRTs. This disagreement reflects variability of opinion and practices pointing toward possible gaps in knowledge, and supports the need for explicit guidelines for the ethical conduct and review of CRTs.

Ethical review of health systems research in low- and middle-income countries: a conceptual exploration

Given that health systems research (HSR) involves different aims, approaches, and methodologies as compared to more traditional clinical trials, the ethical issues present in HSR may be unique or particularly nuanced. This article outlines eight pertinent ethical issues that are particularly salient in HSR and argues that the ethical review process should be better tailored to ensure more efficient and appropriate oversight of HSR with adequate human protections, especially in low- and middle-income countries. The eight ethical areas we discuss include the nature of intervention, types of research subjects, units of intervention and observation, informed consent, controls and comparisons, risk assessment, inclusion of vulnerable groups, and benefits of research. HSR involving human participants is necessary to ensure health systems strengthening and quality of care and to guide public policy intelligently. Health systems researchers must carefully define their intent and goals and openly clarify the values that may influence the premises and design of protocols. As new types of population-level research activities become more commonplace, it is critical that institutional review board (IRB) and research ethics committee (REC) review processes evolve to evaluate these research protocols in ways that address the nuanced features of these studies.

Challenges in the research ethics review of cluster randomized trials: international survey of investigators

BACKGROUND

Cluster randomized trials (CRTs) complicate the interpretation of standard research ethics guidelines for several reasons. For one, the units of allocation, intervention, and observation often may differ within a single trial. In the absence of tailored and internationally accepted ethics guidelines for CRTs, researchers and research ethics committees have no common standard by which to judge ethically appropriate practices in CRTs. Moreover, lack of familiarity with and consideration of the unique features of the CRT design by research ethics committees may cause difficulties in the research ethics review process, and amplify problems such as variability in the requirements and decisions reached by different research ethics committees.

PURPOSE

We aimed to characterize research ethics review of CRTs, examine investigator experiences with the ethics review process, and assess the need for ethics guidelines for CRTs.

METHODS

An electronic search strategy implemented in MEDLINE was used to identify and randomly sample 300 CRTs published in English language journals from 2000 to 2008. A web-based survey with closed- and open-ended questions was administered to corresponding authors in a series of six contacts.

RESULTS

The survey response rate was 64%. Among 182 of 285 eligible respondents, 91% indicated that they had sought research ethics approval for the identified CRT, although only 70% respondents reported research ethics approval in the published article. Nearly one-third (31%) indicated that they have had to meet with ethics committees to explain aspects of their trials, nearly half (46%) experienced variability in the ethics review process in multijurisdictional trials, and 38% experienced negative impacts of the ethics review process on their trials, including delays in trial initiation (28%), increased costs (10%), compromised ability to recruit participants (16%), and compromised methodological quality (9%). Most respondents (74%; 95% confidence interval (CI): 67%-80%) agreed or strongly agreed that there is a need to develop ethics guidelines for CRTs, and (70%; 95% CI: 63%-77%) that ethics committees could be better informed about distinct ethical issues surrounding CRTs.

LIMITATIONS

Thirty-six percent of authors did not respond to the survey. Due to the absence of comparable results from a representative sample of authors of individually randomized trials, it is unclear to what extent the reported challenges result from the CRT design.

CONCLUSIONS

CRT investigators are experiencing challenges in the research ethics review of their trials, including excessive delays, variability in process and outcome, and imposed requirements that can have negative consequences for study conduct. Investigators identified a clear need for ethics guidelines for CRTs and education of research ethics committees about distinct ethical issues in CRTs.

Health promotion in individuals with mental disorders: a cluster preference randomized controlled trial

BACKGROUND

The existing literature on weight management interventions targeting physical activity and healthy eating in mental health care appears to provide only limited evidence. The aim of the study was to examine the effectiveness of a 10-week health promotion intervention, followed by a 6-month follow-up period in individuals with mental disorders living in sheltered housing in the Flanders region (Belgium).

METHODS

The study had a cluster preference randomized controlled design. Twenty-five sheltered housing organisations agreed to participate (16 in the intervention group, nine in the control group). In the intervention group, 225 individuals agreed to participate, while in the control group 99 individuals entered into the study. The main outcomes were changes in body weight, Body Mass Index, waist circumference and fat mass. Secondary outcomes consisted of changes in physical activity levels, eating habits, health-related quality of life and psychiatric symptom severity.

RESULTS

A significant difference was found between the intervention group and the control group regarding body weight (-0.35 vs. +0.22 kg; p=0.04), Body Mass Index (-0.12 vs. +0.08 kg/m2; p=0.04), waist circumference (-0.29 vs. + 0.55 cm; p<0.01), and fat mass (-0.99 vs. -0.12%; p<0.01). The decrease in these outcomes in the intervention group disappeared during the follow up period, except for fat mass. Within the intervention group, a larger decrease in the primary outcomes was found in the participants who completed the intervention. No significant differences between the two groups in changes in the secondary outcomes were found, except for the pedometer-determined steps/day. In the intervention group, the mean number of daily steps increased, while it decreased in the control group.

CONCLUSIONS

The study demonstrated that small significant improvements in the primary outcomes are possible in individuals with mental disorders. Integration of health promotion activities targeting physical activity and healthy eating into daily care are, however, necessary to maintain the promising results.

TRIAL REGISTRATION

This study is registered at ClinicalTrials.gov NCT 01336946.

Researchers' perceptions of ethical challenges in cluster randomized trials: a qualitative analysis

Background

Cluster randomized trials (CRTs) pose ethical challenges for investigators and ethics committees. This study describes the views and experiences of CRT researchers with respect to: (1) ethical challenges in CRTs; (2) the ethics review process for CRTs; and (3) the need for comprehensive ethics guidelines for CRTs.

Methods

Descriptive qualitative analysis of interviews conducted with a purposive sample of 20 experienced CRT researchers.

Results

Informants expressed concern over the potential for bias that may result from requirements to obtain informed consent from research participants in CRTs. Informants suggested that the need for informed consent ought to be related to the type of intervention under study in a CRT. Informants rarely expressed concern regarding risks to research participants in CRTs, other than risks to privacy. Important issues identified in the research ethics literature, including fair subject selection and other justice issues, were not mentioned by informants. The ethics review process has had positive and negative impacts on CRT conduct. Informants stated that variability in ethics review between jurisdictions, and increasingly stringent ethics review in recent years, have hampered their ability to conduct CRTs. Many informants said that comprehensive ethics guidelines for CRTs would be helpful to researchers and research ethics committees.

Conclusions

Informants identified key ethical challenges in the conduct of CRTs, specifically relating to identifying subjects, seeking informed consent, and the use of gatekeepers. These data have since been used to identify topics for in-depth ethical analysis and to guide the development of comprehensive ethics guidelines for CRTs.

Cluster randomized trials of prescription medicines or prescribing policy: public and general practitioner opinions in Scotland

AIMS

To understand public and general practitioner (GP) opinion on the acceptability of randomized policy design (RPD) studies (cluster randomized trials) of prescription medicines in Scotland.

METHODS

We surveyed public opinion on the concept of RPD studies in a sample of 1040 adults to determine acceptability and understand how people feel when changes are made to their medicines. We also surveyed GPs (n = 1034) about the concept of RPD studies as a tool for improving understanding of comparative effectiveness and safety of medicines in the ‘usual care’ setting.

RESULTS

Thirty per cent of people would be happy to receive a letter about randomized policy changes to their therapy, 31% would not mind or had no opinion and 39% would be unhappy. This view was sensitive to the reason for change; effectiveness and safety reasons were most acceptable (96%) and cost saving least acceptable (39%). Only 19% thought randomized policy change was not an acceptable method of determining the best treatments. Eighty-one per cent of respondents were willing for their medical data to be followed up to compare drug treatments (further 10% undecided). Participants reporting long-term medical conditions and those reporting previous changes to drug therapy were more in favour of RPD studies than other participants.

Thirty-three per cent (n = 341) of GPs responded to our survey. Of these, 45% were in favour of RPD studies, 19% were undecided and 36% not in favour.

CONCLUSIONS

The public in Scotland is broadly supportive of the concept of randomized policy design studies of medicines, while there is a spread of opinion among GPs.

Emerging designs in orthopaedics: expertise-based randomized controlled trials

In this article, we discuss the limitations of conventional randomized controlled trials (RCTs) in the surgical field. Surgeons are often believers in certain surgical techniques and therefore can be reluctant to learn new interventions. In expertise-based trials, the patients are randomized to surgeons with expertise in the intervention under investigation. In conventional RCTs, patients are randomized to an intervention, and surgeons will perform this intervention regardless of whether this is the surgery they typically undertake. Conventional randomization may lead to surgery performed by a less experienced or less motivated surgeon, resulting in differential expertise bias. Expertise-based trials can overcome these limitations if potential pitfalls are taken into account.

Participant informed consent in cluster randomized trials: review

BACKGROUND

The Nuremberg code defines the general ethical framework of medical research with participant consent as its cornerstone. In cluster randomized trials (CRT), obtaining participant informed consent raises logistic and methodologic concerns. First, with randomization of large clusters such as geographical areas, obtaining individual informed consent may be impossible. Second, participants in randomized clusters cannot avoid certain interventions, which implies that participant informed consent refers only to data collection, not administration of an intervention. Third, complete participant information may be a source of selection bias, which then raises methodological concerns. We assessed whether participant informed consent was required in such trials, which type of consent was required, and whether the trial was at risk of selection bias because of the very nature of participant information.

METHODS AND FINDINGS

We systematically reviewed all reports of CRT published in MEDLINE in 2008 and surveyed corresponding authors regarding the nature of the informed consent and the process of participant inclusion. We identified 173 reports and obtained an answer from 113 authors (65.3%). In total, 23.7% of the reports lacked information on ethics committee approval or participant consent, 53.1% of authors declared that participant consent was for data collection only and 58.5% that the group allocation was not specified for participants. The process of recruitment (chronology of participant recruitment with regard to cluster randomization) was rarely reported, and we estimated that only 56.6% of the trials were free of potential selection bias.

CONCLUSIONS

For CRTs, the reporting of ethics committee approval and participant informed consent is less than optimal. Reports should describe whether participants consented for administration of an intervention and/or data collection. Finally, the process of participant recruitment should be fully described (namely, whether participants were informed of the allocation group before being recruited) for a better appraisal of the risk of selection bias.

Social science and ethics review: A question of practice not principle

In his article ‘The case against ethics review in the social sciences’, Schrag asserts that the social sciences should not be subject to ethical review. He recounts a number of examples where ethical review has seemingly failed. He further suggests some alternative models for dealing with ethical review in the social sciences. Finally, he concludes, and we concur, that there is a lack of empirical evidence as to the benefit of research ethics review.

The Ottawa Statement on the Ethical Design and Conduct of Cluster Randomized Trials

The Ottawa Ethics of Cluster Trials Consensus Group sets out 15 recommendations for the ethical design and conduct of cluster randomized trials.

Does clinical equipoise apply to cluster randomized trials in health research?

This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, Weijer and colleagues set out six areas of inquiry that must be addressed if the cluster trial is to be set on a firm ethical foundation. This paper addresses the third of the questions posed, namely, does clinical equipoise apply to CRTs in health research? The ethical principle of beneficence is the moral obligation not to harm needlessly and, when possible, to promote the welfare of research subjects. Two related ethical problems have been discussed in the CRT literature. First, are control groups that receive only usual care unduly disadvantaged? Second, when accumulating data suggests the superiority of one intervention in a trial, is there an ethical obligation to act?In individually randomized trials involving patients, similar questions are addressed by the concept of clinical equipoise, that is, the ethical requirement that, at the start of a trial, there be a state of honest, professional disagreement in the community of expert practitioners as to the preferred treatment. Since CRTs may not involve physician-researchers and patient-subjects, the applicability of clinical equipoise to CRTs is uncertain. Here we argue that clinical equipoise may be usefully grounded in a trust relationship between the state and research subjects, and, as a result, clinical equipoise is applicable to CRTs. Clinical equipoise is used to argue that control groups receiving only usual care are not disadvantaged so long as the evidence supporting the experimental and control interventions is such that experts would disagree as to which is preferred. Further, while data accumulating during the course of a CRT may favor one intervention over another, clinical equipoise supports continuing the trial until the results are likely to be broadly convincing, often coinciding with the planned completion of the trial. Finally, clinical equipoise provides research ethics committees with formal and procedural guidelines that form an important part of the assessment of the benefits and harms of CRTs in health research.

Inadequate reporting of research ethics review and informed consent in cluster randomised trials: review of random sample of published trials

OBJECTIVES

To investigate the extent to which authors of cluster randomised trials adhered to two basic requirements of the World Medical Association's Declaration of Helsinki and the International Committee of Medical Journal Editors' uniform requirements for manuscripts (namely, reporting of research ethics review and informed consent), to determine whether the adequacy of reporting has improved over time, and to identify characteristics of cluster randomised trials associated with reporting of ethics practices.

DESIGN

Review of a random sample of published cluster randomised trials from an electronic search in Medline.

SETTING

Cluster randomised trials in health research published in English language journals from 2000 to 2008. Study sample 300 cluster randomised trials published in 150 journals.

RESULTS

77 (26%, 95% confidence interval 21% to 31%) trials failed to report ethics review. The proportion reporting ethics review increased significantly over time (P<0.001). Trials with data collection interventions at the individual level were more likely to report ethics review than were trials that used routine data sources only (79% (n=151) v 55% (23); P=0.008). Trials that accounted for clustering in the design and analysis were more likely to report ethics review. The median impact factor of the journal of publication was higher for trials that reported ethics review (3.4 v 2.3; P<0.001). 93 (31%, 26% to 36%) trials failed to report consent. Reporting of consent increased significantly over time (P<0.001). Trials with interventions targeting participants at the individual level were more likely to report consent than were trials with interventions targeting the cluster level (87% (90) v 48% (41); P<0.001). Trials with data collection interventions at the individual level were more likely to report consent than were those that used routine data sources only (78% (146) v 29% (11); P<0.001).

CONCLUSIONS

Reporting of research ethics protections in cluster randomised trials is inadequate. In addition to research ethics approval, authors should report whether informed consent was sought, from whom consent was sought, and what consent was for.

Ethical issues posed by cluster randomized trials in health research

The cluster randomized trial (CRT) is used increasingly in knowledge translation research, quality improvement research, community based intervention studies, public health research, and research in developing countries. However, cluster trials raise difficult ethical issues that challenge researchers, research ethics committees, regulators, and sponsors as they seek to fulfill responsibly their respective roles. Our project will provide a systematic analysis of the ethics of cluster trials. Here we have outlined a series of six areas of inquiry that must be addressed if the cluster trial is to be set on a firm ethical foundation:

1. Who is a research subject?

2. From whom, how, and when must informed consent be obtained?

3. Does clinical equipoise apply to CRTs?

4. How do we determine if the benefits outweigh the risks of CRTs?

5. How ought vulnerable groups be protected in CRTs?

6. Who are gatekeepers and what are their responsibilities?

Subsequent papers in this series will address each of these areas, clarifying the ethical issues at stake and, where possible, arguing for a preferred solution. Our hope is that these papers will serve as the basis for the creation of international ethical guidelines for the design and conduct of cluster randomized trials.

Electronic search strategies to identify reports of cluster randomized trials in MEDLINE: low precision will improve with adherence to reporting standards

Background

Cluster randomized trials (CRTs) present unique methodological and ethical challenges. Researchers conducting systematic reviews of CRTs (e.g., addressing methodological or ethical issues) require efficient electronic search strategies (filters or hedges) to identify trials in electronic databases such as MEDLINE. According to the CONSORT statement extension to CRTs, the clustered design should be clearly identified in titles or abstracts; however, variability in terminology may make electronic identification challenging. Our objectives were to (a) evaluate sensitivity ("recall") and precision of a well-known electronic search strategy ("randomized controlled trial" as publication type) with respect to identifying CRTs, (b) evaluate the feasibility of new search strategies targeted specifically at CRTs, and (c) determine whether CRTs are appropriately identified in titles or abstracts of reports and whether there has been improvement over time.

Methods

We manually examined a wide range of health journals to identify a gold standard set of CRTs. Search strategies were evaluated against the gold standard set, as well as an independent set of CRTs included in previous systematic reviews.

Results

The existing strategy (randomized controlled trial.pt) is sensitive (93.8%) for identifying CRTs, but has relatively low precision (9%, number needed to read 11); the number needed to read can be halved to 5 (precision 18.4%) by combining with cluster design-related terms using the Boolean operator AND; combining with the Boolean operator OR maximizes sensitivity (99.4%) but would require 28.6 citations read to identify one CRT. Only about 50% of CRTs are clearly identified as cluster randomized in titles or abstracts; approximately 25% can be identified based on the reported units of randomization but are not amenable to electronic searching; the remaining 25% cannot be identified except through manual inspection of the full-text article. The proportion of trials clearly identified has increased from 28% between the years 2000-2003, to 60% between 2004-2007 (absolute increase 32%, 95% CI 17 to 47%).

Conclusions

CRTs should include the phrase "cluster randomized trial" in titles or abstracts; this will facilitate more accurate indexing of the publication type by reviewers at the National Library of Medicine, and efficient textword retrieval of the subset employing cluster randomization.