Long-Term Follow-Up Of Patients Treated With Aminosalicylates For Ulcerative Colitis: Predictive Factors Of Response: An Observational Case-Control Study

Background Knowing patients' ulcerative colitis history is essential to selecting the appropriate therapy according to risk stratification. Objective To evaluate and identify predictive factors of non-response to aminosalicylates judged as the need for a step-up approach over time.Methods A case-control study of ulcerative colitis patients treated with aminosalicylates after the diagnosis of disease flare included in the ENEIDA single-centre registry from 1997 to 2017. Long-term treatment maintenance with aminosalicylates and higher therapeutic requirements were recorded. The cumulative incidence of treatment escalation was estimated using Kaplan-Meier curves and compared by the log-rank test. Cox regression analysis was performed to identify predictive factors of treatment with immunomodulators, biological agents or surgery. Results A total of 457 patients were included, of whom 28% (n = 126) were non-responders to aminosalicylates. The cumulative probability for a step-up approach within 20 years of follow up was 35%, mainly due to steroid-dependent colitis. Risk factors for treatment escalation were age <= 27 years (hazard ratio 2.31, 95% confidence interval 1.36-3.92), extensive colitis (hazard ratio 1.65, 95% confidence interval 1.04-2.60), Mayo endoscopic subscore >= 2 (hazard ratio 1.45, 95% confidence interval 1.02-2.06) and extraintestinal manifestations (hazard ratio 2.04, 95% confidence interval 1.03-4.05).Conclusions Aminosalicylates represent an effective maintenance therapy. Younger age, extensive colitis, endoscopic disease severity and extraintestinal manifestations are risk factors for higher therapeutic requirements.