The ethics of cluster randomized trials: response to a proposal for revision of the Ottawa Statement

Why and when should we cluster randomize?

A cluster randomized trial is defined as a randomized trial in which intact social units of individuals are randomized rather than individuals themselves. Outcomes are observed on individual participants within clusters (such as patients). Such a design allows assessing interventions targeting cluster-level participants (such as physicians), individual participants or both. Indeed, many interventions assessed in cluster randomized trials are actually complex ones, with distinct components targeting different levels. For a cluster-level intervention, cluster randomization is an obvious choice: the intervention is not divisible at the individual-level. For individual-level interventions, cluster randomization may nevertheless be suitable to prevent group contamination, for logistical reasons, to enhance participants' adherence, or when objectives pertain to the cluster level. An unacceptable reason for cluster randomization would be to avoid obtaining individual consent. Indeed, participants in cluster randomized trials have to be protected as in any type of trial design. Participants may be people from whom data are collected, but they may also be people who are intervened upon, and this includes both patients and physicians (for example, physicians receiving training interventions). Consent should be sought as soon as possible, although there may exist situations where participants may consent only for data collection, not for being exposed to the intervention (because, for instance, they cannot opt-out). There may even be situations where participants are not able to consent at all. In this latter situation a waiver of consent must be granted by a research ethics committee.

[French version of The Ottawa Statement on the Ethical Design and Conduct of Cluster Randomized Trials, in a French law context]

INTRODUCTION

There is growing evidence on the ethical challenges raised by cluster randomized trials. This specificity is not reflected in the legal texts regulating research, which creates difficulties for researchers implementing these experimental designs. The Ottawa Statement (Weijer et al. 2012) aims to provide detailed guidance on the ethical design, conduct and assessment of cluster trials. More broadly aims to help research stakeholders and decision-makers to make informed ethical decisions regarding the particularity of these experimental designs. It seems that this international statement, written in English, is not sufficiently accessible to all of the French professionals involved in health research. The aim of this article is to provide these professionals with a contextualized and illustrated French translation of the "Ottawa statement".

METHOD

. The "complex design" working group of the RECaP network (Research in Clinical Epidemiology and Public Health), carried out this work. A first version was discussed by the authors in several meetings. It was completed by contextual explanations and examples of French studies currently conducted by the authors. The final version was obtained by consensus and validated by the group.

RESULTS

. This work reports 15 recommendations grouped into 7 key questions: How to justify cluster design? How to submit an article to an ethics committee? How to identify research participants? How and when to obtain informed consent? Who are the gatekeepers? How to assess benefits and harm? How to protect vulnerable participants? Each of these recommendations is specific to cluster trials. The recommendations are explained and detailed through concrete examples.

CONCLUSION

Without interfering with current French laws, this work provides a framework for the organization, conduct and ethical assessment of cluster randomized trials in France. In the present-day context, it is essential that all concerned groups can base their decisions on recommendations in line with the elementary principles of health research ethics.

Ethical care requires pragmatic care research to guide medical practice under uncertainty

BACKGROUND

The current research-care separation was introduced to protect patients from explanatory studies designed to gain knowledge for future patients. Care trials are all-inclusive pragmatic trials integrated into medical practice, with no extra tests, risks, or cost, and have been designed to guide practice under uncertainty in the best medical interest of the patient.

PROPOSED REVISION

Patients need a distinction between validated care, previously verified to provide better outcomes, and promising but unvalidated care, which may include unnecessary or even harmful interventions. While validated care can be practiced normally, unvalidated care should only be offered within declared pragmatic care research, designed to protect patients from harm. The validated/unvalidated care distinction is normative, necessary to the ethics of medical practice. Care trials, which mark the distinction and allow the tentative use of promising interventions necessarily involve patients, and thus the design and conduct of pragmatic care research must respect the overarching rule of care ethics "to always act in the best medical interest of the patient." Yet, unvalidated interventions offered in contexts of medical uncertainty cannot be prescribed or practiced as if they were validated care. The medical interests of current patients are best protected when unvalidated practices are restricted to a care trial protocol, with 1:1 random allocation (or "hemi-prescription") versus previously validated care, to optimize potential benefits and minimize risks for each patient.

CONCLUSION

Pragmatic trials can regulate medical practice by providing (i) a transparent demarcation between unvalidated and validated care; (ii) norms of medical conduct when using tests and interventions of yet unknown benefits in practice; and eventually (iii) a verdict regarding optimal care.

The moral and legal status of Health Care Workers in Cluster Randomized Trials: a response to Weijer and Taljaard

In 2012, Weijer et al published "The Ottawa Statement on the ethical design and conduct of cluster randomized trials". In 2015, we reflected on this statement and argued that three recommendations in this statement need to be further refined. Weijer and Taljaard have responded to our comments in this issue of the journal. They agree with one of the proposed revisions but not with two others. In this commentary, we argue that the main reason why there is disagreement about two of our refinements is that we have different views on the moral and legal status of the health care workers as "research participants" in cluster randomized trials (CRTs). In this commentary, we clarify misunderstandings about our view expressed in 2015 and elaborate on the positions of health care workers in CRTs. We argue that there is sufficient reason to doubt whether the rights and interests of health care workers (HCWs) should be protected by means of ethics guidance documents and laws on human subjects research. Their interests are protected in the first place by professional codes of conduct which ensure that they cannot provide substandard care. Furthermore, protection of HCWs by ethics guidance on human subjects research will create an enormous burden for principle investigators and research ethics committees. Further debate is essential to determine how the interests of HCWs in CRTs can be protected best.