Scoring Indices for Perianal Fistulising Crohn’s Disease: A Systematic Review

Abstract

Background & Aims In this systematic review we summarize existing scoring indices for assessing disease activity and quality of life in perianal fistulizing Crohn’s disease (PFCD) and highlight gaps in the literature. Methods MEDLINE, EMBASE, and CENTRAL were searched from 24 August 2022 to identify studies evaluating clinical, radiological, or patient-reported outcome measures (PROMS) in PFCD. The primary objective was to identify all available scoring indices and describe the operating properties of these indices. Results Fifty-three studies reported on the use of one clinical index (Perianal Disease Activity Index: PDAI), three PROMs and ten radiological indices. Twenty-five studies evaluated the operating properties of these indices. The PDAI demonstrated content validity, construct validity and responsiveness but criterion validity or reliability were not assessed. The Van Assche index (VAI), modified VAI and the Magnetic Resonance Index for Assessing Fistulas in Patients with CD (MAGNIFI-CD) were the most studied radiological indices. These indices demonstrated responsiveness and reliability. The VAI and MAGNIFI-CD demonstrated construct validity. Criterion and content validity and feasibility have not been assessed. Among the three PROMs, the Crohn’s Anal Fistula Quality of Life index demonstrated content and construct validity, inter-observer reliability and responsiveness. Criterion validity, intra-observer reliability and feasibility have not been assessed for this index. Conclusions There are no fully valid, reliable, and responsive clinical disease or radiological indices for PFCD. Although the radiological indices demonstrated responsiveness and reliability, well-defined cut-offs for response and remission are lacking. Future research should focus on establishing standardized definitions and thresholds for outcomes.