Background and aims: Since the 1980s, many studies have evaluated the efficacy of therapies to improve the outcomes of patients with perianal Crohn's disease. We performed a systematic review to describe the evolution of endpoints in perianal fistulizing Crohn's disease. Efficacy outcomes, definitions and measurement tools were assessed.
Methods: Electronic databases were searched up to November 1, 2020. All published randomized placebo-controlled trials enrolling patients with perianal fistula and Crohn's disease were eligible for inclusion. Ongoing randomized clinical trials were also described.
Results: Nineteen randomized controlled trials were included. Clinical efficacy endpoints were reported in all trials. Clinical response was the most frequent primary endpoint [6/19 studies, 31.6%], followed by clinical remission in four studies [21%]. Clinical response was defined as closure of at least 50% of fistulas, while remission was defined as closure of all fistulas. A combined clinical and radiological primary endpoint was used to assess fistula healing in four studies [21%]. The Perianal Disease Activity Index was a primary endpoint in only one study [5.5%]. In addition, eight ongoing controlled trials were identified. Combined clinical and radiological remission was the most frequent primary endpoint in these studies [4/8, 50%].
Conclusion: In this systematic review, significant changes in outcomes used in randomized clinical trials of perianal Crohn's disease were observed. Radiological endpoints are increasingly used in perianal fistulizing Crohn's disease trials.
Keywords: Crohn’s disease; disease activity; endpoints; perianal fistula.
© The Author(s) 2021. Published by Oxford University Press on behalf of European Crohn’s and Colitis Organisation. All rights reserved. For permissions, please email: journals.permissions@oup.com.