Are the people who take part in randomised controlled trials real? A response to Stewart‐Brown et al.

Purpose – This paper's aim is to explore the uses and limitations of randomised controlled trials (RCTs) for evaluating complex interventions, with a particular focus on sample recruitment and retention issues. Design/methodology/approach – This is an invited critique of a previous paper. Findings – RCTs have many limitations. It is particularly important to consider issues relating to the sample they recruit and retain. Nonetheless, they remain a uniquely powerful way to exclude other potential explanations for outcomes and therefore provide robust evidence for the effectiveness of specific interventions. Originality/value – It is hoped that vigorous debate may contribute to a deepened understanding of the nature, limitations and potential contribution of RCTs to understanding the impact of different ways of helping people.