Mesalazine in Inflammatory Bowel Disease and COVID-19: Hospitalization and Adverse In-Hospital Outcomes Based on Nationwide Data.

BACKGROUND We assessed whether 5-aminosalicylic acid (5-ASA), as treatment for inflammatory bowel disease (IBD), was associated with an increase in hospitalization for coronavirus disease 2019 and adverse in-hospital outcomes. METHODS This was a Danish nationwide register study. The study population consisted of all patients with an IBD diagnosis between March 1, 2010, and March 1, 2020, and living in Denmark on March 1, 2020. Patients with IBD treated with 5-ASA (exposed) were compared with patients not receiving 5-ASA (unexposed). RESULTS We identified 60 242 patients with IBD; 15 635 (40.5%) with ulcerative colitis (UC) and 964 (4.5%) with Crohn's disease (CD) were exposed to 5-ASA. For patients with UC who were 5-ASA exposed, the hazard ratio of hospitalization was 1.18 (95% confidence interval, 0.79-1.78). In-hospital outcomes were not statistical significant from those not exposed to 5-ASA (median length of hospital stay 5.6 days vs 7.2 days), mechanical ventilation (0% vs 14%), continuous positive airway pressure (7.9% vs 9.4%), and in-hospital mortality (21.1% vs 17.2%). For patients with CD, the hazard ratio of hospitalization was 2.25 (95% confidence interval, 1.02-4.97). We found no statistically significant difference in length of hospital stay (7.1 days vs 3.9 days), mechanical ventilation (0% vs 1.8%), use of continuous positive airway pressure (0% vs 1.8%), or in-hospital mortality (0% vs 9%) between exposed and unexposed patients. CONCLUSIONS Patients with UC, treated with 5-ASA, had no increased risk of hospitalization for coronavirus disease 2019 or more adverse in-hospital outcomes. In patients with CD, 5-ASA may be associated with an increased risk of hospitalization but not with more adverse in-hospital outcomes.