Uncertainty about effects is a key factor influencing institutional review boards' approval of clinical studies

PurposeTo investigate factors, which influence institutional review boards' (IRBs') decision to approve or not approve clinical studies, a nationwide vignette-based online survey of IRB members was conducted.MethodsA factorial design was used, whereby seven aspects of each hypothetical study were randomly varied in 15 phrases in each vignette to produce unique vignettes. Participants indicated the degree of study approval and described factors influencing approval decision. Qualitative responses were thematically content analyzed.ResultsSixteen themes were obtained from 208 participants from 42 institutions. Uncertainty, adherence, study design, and harms were frequently and intensely cited to influence study approval. Analysis of two extreme subgroups (approvers vs. nonapprovers) showed that uncertainty influenced approval decisions, odds ratios (OR) = 3.5 (95% confidence interval [CI], 1.3–9.8) and OR = 3.2 (95% CI, 1.1–8.9), respectively, based on theme frequency and theme intensity, ignoring multiple observations per person. Taking into consideration multiple observations per person, similar results were obtained for uncertainty: OR = 8.9 (95% CI, 0.93–85.4).ConclusionsPerceived uncertainty about benefits and harms of a proposed intervention is a key driver in IRB members' approval of clinical trials. This, in turn, calls for improved standardization in the communications of information on benefits and harms in the research protocols considered by the IRBs.