Most tumour necrosis factor inhibitor trials in rheumatology are undeservedly called efficacy and safety trials: a survey of power considerations

Abstract

Objectives: Many randomized clinical trials (RCTs) are labelled efficacy and safety while due consideration for power is provided only for efficacy outcomes. This in turn necessitates a discussion of the inadequacy of sample size (type II error) for identifying harm. This is particularly important in RCTs of TNF inhibitors as harm related to these agents is still a matter of debate.