Patient-Reported Outcome and Clinical Scores Are Equally Accurate in Predicting Mucosal Healing in Ulcerative Colitis: A Prospective Study

Background Optimal management of patients with ulcerative colitis (UC) requires the accurate, objective assessment of disease activity. Aims We aimed to determine how strong patient-reported outcomes, clinical scores and symptoms correlate with endoscopy and biomarkers for assessment of disease activity in patients with UC. Methods Consecutive patients with UC followed at the McGill University IBD Center and referred for endoscopy (surveillance or flare) were included prospectively between September 2018 and August 2020. Patient-reported outcome (PRO2), partial Mayo, Simple Clinical Colitis Activity Index (SCCAI), Mayo endoscopic subscore (MES) and Baron and Ulcerative Colitis Endoscopic Index of Severity (UCEIS) scores were calculated. C-reactive protein (CRP) and fecal calprotectin (FCAL) were collected. Results A total of 171 patients with UC [age: 49(IQR:38–61) years, female: 46.2%, 57.3% extensive disease, 42.7% on biologicals] were included prospectively. Rectal bleeding (RBS), stool frequency (SF) subscore of 0, or total PRO2 remission (RBS0 and SF ≤ 1), partial Mayo (≤ 2) and SCCAI (≤ 2.5) remission were similarly associated with mucosal healing defined by MES (0 or ≤ 1), Baron (0 or ≤ 1) or UCEIS (≤ 3) scores in ROC analysis (AUC:0.93–0.72). There was a moderate-to-strong agreement between MES Baron and UCEIS ( K = 0.91–0.41). A UCEIS of ≤ 3 was identified as the best cutoff to clinical or endoscopic remission. Agreement between CRP and clinical remission or endoscopic healing (MES/Baron) was poor ( K ~ 0.2), while agreement between FCAL and RBS-PRO2 or MES/Baron/UCEIS was moderate to strong ( K = 0.44–0.70). Conclusions Agreement between RBS, SF, PRO2, partial Mayo and SCCAI in predicting endoscopic healing was moderate to strong, while no clinically meaningful difference was found in accuracy across the scores and definitions. FCAL, but not CRP, was associated to clinical and endoscopic remission.