Preferred designs, outcomes, and analysis strategies for treatment trials in idiopathic recurrent acute pancreatitis

IRAP is a complicated area to study, and, in part, this is the reason there is a paucity of IRAP clinical trials. However, in reviewing the literature and weighing methodologic and statistical concerns, a time-to-event analysis of any recurrence of pancreatitis appears to be the most sound and practical end point for a prospective study. The preferred design would be a stratified (eg, single vs recurrent [or other dichotomy of baseline attack frequency] and/or a prior cholecystectomy versus no prior cholecystectomy) randomized controlled (preferably blinded) trial, likely of at least 3 years' duration, with a stratified time-to-event primary analysis. A multicenter registry (as is currently being developed by the IRAP Interest Group) may be able to answer some questions and has the possible advantage of efficiency in using a single patient for the assessment of more than one intervention but has a more complicated analysis and is prone to confounding by unknown confounders (which randomization is best to balance).