Factors Associated With Nonadherence to Thiopurines in Adolescent and Adult Patients With Inflammatory Bowel Disease

Objectives: We hypothesised that nonadherence to thiopurines is more common in adolescents than in adults with inflammatory bowel disease. Methods: We sought factors associated with thiopurine nonadherence defined by thiopurine metabolite levels. Results: Multivariate logistic regression confirmed that adolescents (odds ratio [OR] 4.6 [95% confidence interval [CI] 1.9-11.5]; P < 0.01) compared with adults, patients with Crohn disease (OR 3.3 [CI 1.1-10.5] P = 0.04) compared with ulcerative colitis, and patients living in more socially deprived areas (OR 1.03 [CI 1.0-1.1] P = 0.02) were more likely to be nonadherent to thiopurines. Conclusions: Adolescents are more frequently nonadherent than adults: prospective studies are required to determine the reasons for nonadherence in adolescents.