How are randomized clinical trials ethically justified? A systematic scoping review and thematic analysis of reasons that ethically justify randomized clinical trials

Network meta-analysis can inform the ethical evaluation of trials that randomise away from standard of care: The case of symptomatic carotid stenosis

OBJECTIVE

Little guidance exists on the conduct of randomised clinical trials (RCT) that seek to randomise patients away from standard of care. We sought to test the technique of network meta-analysis (NMA) to ascertain best available evidence for the purposes of informing the ethical evaluation of RCTs under these circumstances. We used the example of RCTs for patients with symptomatic, moderate to severe carotid stenosis that seek to compare surgical intervention plus medical therapy (standard of care) versus medical therapy (less than standard of care).

STUDY DESIGN AND SETTING

Network meta-analysis of RCTs of adults with symptomatic carotid artery stenosis of 50%-99% who were treated with carotid endarterectomy (CEA), carotid artery stenting (CAS), or medical therapy (MT). The primary outcome was any stroke or death until end of follow-up, and secondary outcome was 30-day risk of ipsilateral stroke/death.

RESULTS

We analysed eight studies, with 7187 subjects with symptomatic moderate/severe stenosis (50%-99%). CEA was more efficacious than MT (HR = 0.82, 95% credible intervals [95% CrI] = 0.73-0.92) and CAS (HR 0.73, 95% CrI = 0.62-0.85) for the prevention of any stroke/death. At 30 days, the odds of experiencing an ipsilateral stroke/death were significantly lower in the CEA group compared to both MT (OR = 0.58, 95% CrI = 0.47-0.72) and CAS (OR = 0.68, 95% CrI = 0.55-0.83).

CONCLUSION

Our results support the feasibility of using NMA to assess best available evidence to inform the ethical evaluation of RCTs seeking to randomise patients away from standard of care. Our results suggest that a strong argument is required to ethically justify the conduct of RCTs that seek to randomise patients away from standard of care in the setting of symptomatic moderate to severe carotid stenosis.

What do we talk about when we talk about "equipoise"? Stakeholder interviews assessing the use of equipoise in clinical research ethics

INTRODUCTION

Equipoise, generally defined as uncertainty about the relative effects of the treatments being compared in a trial, is frequently referenced as an ethical standard for the conduct of randomized clinical trials. However, it seems to be defined in several different ways and may be used differently by different individuals. We explored how clinical researchers, chairs of research ethics boards, and philosophers of science define and reason with this term.

METHODS

We completed semi-structured interviews about clinical trial ethics with 15 clinical researchers, 15 research ethics board chairs, and 15 philosophers of science/bioethicists. Each participant was asked a standardized set of 10 questions, 4 of which were specifically about equipoise. All interviews were conducted telephonically and transcribed. Responses were grouped and analysed via a modified grounded theory method.

RESULTS

Forty-three respondents defined equipoise in 7 logically distinct ways, and 2 respondents could not explicitly define it. The most common definition, offered by 14 respondents (31%), defined "equipoise" as a disagreement at the level of a community of physicians. There was significant variability in definitions offered between and within groups. When asked how they would "operationalize" equipoise - i.e. check or test for its presence - respondents provided 7 alternatives, the most common being in relation to a literature review (15/45, 33%). The vast majority of respondents (35/45, 78%) felt the concept was helpful, though many acknowledged that the lack of a clear definition or operationalization was problematic.

CONCLUSION

There is significant variation in definitions of equipoise offered by respondents, suggesting that parties within groups and between groups may be referring to different concepts when they reference "equipoise". This non-uniformity may impact fairness and transparency and opens the door to potential ethical problems in the evaluation of clinical trials - for instance, a patient may understand equipoise very differently than the researchers enrolling her in a trial, which could cause her agreement to participate to be based upon false premises.