An example of problems that arise from clinical trials and how to avoid them

摘要

P3MC is a randomised double-blind, parallel-group placebo-controlled trial of propranolol and pizotifen for prevention of migraine in children aged five to 16 years with frequent migraine referred to secondary care outpatients. It is designed as two two-arm trials, with allocation ratio of 2:1 for each comparison (of propranolol versus placebo and pizotifen versus placebo). From a participant's perspective, therefore, it appears as a single three-arm trial with equal allocation. Because both active trial treatments have been in common clinical use for this indication for over 20 years, the trial does not expose participants to a new therapeutic risk.