BACKGROUND A gap remains in documenting the impact of anti-tumor necrosis factor therapy on disease burden in ulcerative colitis(UC) patients treated in a real-world setting. The use of patient-reported outcomes(PROs) has been discussed as a primary endpoint in the context of the FDA PRO Guidance,for labelling purposes. Specifically,the efficacy and safety of adalimumab have been demonstrated in pivotal trials; however,data are needed to understand how clinical results translate into improvements in key aspects of the daily lives of UC patients,such as symptoms,health-related quality of life(HRQo L),and disability.AIM To assess real-world effectiveness of adalimumab on PRO measures in patients with moderate-to-severe UC.METHODS UCan ADA was a single arm,prospective,1-year multicenter Canadian post-marketing observational study in which multiple PRO questionnaires were completed—with psychologic distress/depression symptoms as the primary endpoint—by patients with moderate-to-severe UC. Assessments were performed during patients’ routine care visit schedule,which was at the initiation of adalimumab(baseline),after induction(approximately 8 wk),and 52 wk after baseline. Additional optional assessments between weeks 8 and 52 were collected at least once but no more than two times during this period. Serious safety events and per-protocol adverse events were collected.RESULTS From 23 Canadian centres,100 patients were enrolled and 48 completed the study. Measured with the Patient Health Questionnaire–9 items at week 52,61.5%(40/65) [95% confidence interval(CI): 49.7%-73.4%] of the patients improved in psychologic distress/depression symptoms,which was slightly higher in completers [65.9%(29/44); 95%CI: 51.9%-79.9%)]. At week 52,clinical response and clinical remission were achieved respectively by 65.7%(44/73) and 47.8%(32/73) of the patients. The odds of improving depressive symptoms for those achieving a clinical remission at week 52 was 7.94 higher compared with those not achieving a clinical remission(CI: 1.42,44.41; P = 0.018). Significant changes from baseline to weeks 8 and 52 were observed in disability,HRQo L,and fatigue. Meaningful improvement was reported in work impairment.CONCLUSION At week 52,over 60% of the UCan ADA patients had depressive symptoms significantly reduced,as well as HRQo L,fatigue symptoms,and work impairment improved. No new safety signals were detected.