Studies of compliance with delayed‐release mesalazine therapy in patients with inflammatory bowel disease

Abstract

Background: Non‐compliance with maintenance mesalazine therapy may be a risk factor for relapse in inflammatory bowel disease, but the prevalence and determinants of non‐compliance are unknown. Aim: To study the prevalence and determinants of non‐compliance in patients with inflammatory bowel disease. Methods: Out‐patients receiving delayed‐release mesalazine were studied. Compliance was determined by direct enquiry and by analysis of urine samples for 5‐aminosalicylic acid/N‐acetyl‐5‐aminosalicylic acid. Potential determinants of compliance were assessed. Results: Ninety‐eight patients were studied. Forty‐two patients (43%) reported taking < 80% of their prescribed dose. Logistic regression revealed the independent predictors of non‐compliance to be three‐times daily dosing [odds ratio (OR), 3.1; 95% confidence interval (CI), 1.8–8.4] and full‐time employment (OR, 2.7; 95% CI, 1.1–6.9). Urine from 12 patients (12%) contained no detectable 5‐aminosalicylic acid/N‐acetyl‐5‐aminosalicylic acid, and 18 patients (18%) had levels below those expected. Depression was the only independent predictor of complete non‐compliance (OR, 10.5; 95% CI, 1.8–79.0), and three‐times daily dosing was the only independent predictor of partial non‐compliance (OR, 3.7; 95% CI, 1.8–8.9). Self‐reporting correctly identified 66% of patients judged to be non‐compliant on urinary drug measurement. Conclusions: Non‐compliance with maintenance mesalazine therapy is common in patients with inflammatory bowel disease. Three‐times daily dosing and full‐time employment are predictors of partial non‐compliance, whilst depression is associated with complete non‐compliance. Self‐reporting detects most non‐compliant patients.