Adherence to advanced therapies in inflammatory bowel diseases: Real-world rates and predictors of non-adherence

BACKGROUND AND AIM: Biologics and small molecules are key treatments for inflammatory bowel diseases (IBD), but long-term adherence remains challenging. This study assessed adherence to biological and small-molecule therapies and identified predictors of non-adherence in IBD patients. METHODS: Treatment schedules (January-October 2024) were collected for all patients receiving biologics or small molecules. Infusion dates were retrieved from administrative databases, while patients on subcutaneous therapy were contacted by phone. For oral agents, adherence was measured by pill counts at resupply. Clinical and demographic data were recorded. Non-adherence rates were compared across therapies and analyzed using odds ratios. RESULTS: The study included 342 patients: 127 with ulcerative colitis, 208 with Crohn's disease, 4 with unclassified colitis, and 3 with pouchitis. Treatments included Infliximab (n = 117), Adalimumab (n = 55), Vedolizumab (n = 55), Ustekinumab (n = 100), Golimumab (n = 3), Risankizumab (n = 2), and small molecules (n = 10). Overall non-adherence was 30.4 % (104/342). Of 1,035 planned administrations, 125 (12 %) were missing. Subcutaneous/oral therapies showed higher missed-dose rates than intravenous regimens (p < 0.0001). Higher education level (OR 2.2, 95 % CI 1.62-4.99) and subcutaneous therapy (OR 3.75, 95 % CI 1.83-7.66) independently predicted non-adherence. CONCLUSION: Our study found a low non-adherence rate for biological and small molecule therapies in IBD patients. Higher education level and subcutaneous treatment emerged as potential risk factors for non-adherence.