Comparative Effectiveness Research: A Roadmap to Sail the Seas of IBD Therapies.

The drug pipeline for the treatment of inflammatory bowel disease (IBD) has dramatically expanded over the last two decades, and it is expected to further grow in the upcoming years with the introduction of new agents with different mechanisms of action. However, such an increase of therapeutic options needs to be paralleled with an appropriate development of research to help physicians in the decision-making process when choosing which drug to prescribe. On the population level, comparative effectiveness research (CER) is intended to explore and identify relevant differences-in terms of both efficacy and safety outcomes-amongst different therapeutic regimens and/or strategies, in order to find the correct placement for each treatment in the therapeutic algorithm. CER revolves around three cornerstones: network meta-analyses, head-to-head trials and real-world studies, each of which has specific pros and cons, and can therefore offer answers to different questions. In this review, we aim to provide an overview on the methodological features specific to each of these research approaches, as well as to illustrate the main findings coming from CER on IBD target therapies (i.e., biologics and small molecules) and to discuss their appropriate interpretation.