Randomised controlled trials in severe asthma: selection by phenotype or stereotype

We read with interest the paper by Brown et al. [1], which confirms the lack of external validity in randomised controlled trials (RCTs) of phenotype targeted biological therapies in severe asthma. Our team conducted a very similar study several years ago and we are pleased the present study reaches consistent findings [2]. Of 593 asthmatic patients from the French COBRA cohort, 303 were considered severe asthmatics (Global Initiative for Asthma criteria [3]) and were assessed against eligibility criteria of RCTs targeting severe asthma. The eligibility rates ranged from 0.27% to 10.71%. The data presented by Brown et al. [1] highlight the lack of improvement over the past years. These findings raise major ethical issues in medical decisions, at both the individual and collective levels. The poor representability of real-life patients in severe asthma RCTs is closely related to the selection of end-points. A composite criterion to evaluate the benefit/risk balance rather than separate end-points would broaden the eligible population. http://ow.ly/JLel30naY1Y