Purpose: We conducted a prospective study to determine the effects of nonadherence with mesalamine among patients with quiescent ulcerative colitis.
Methods: We followed a cohort of 99 consecutive patients who had ulcerative colitis in remission for more than 6 months and who were taking maintenance mesalamine. Medication adherence rates were calculated based on pharmacy records and a validated formula. Nonadherence was defined as refilling less than 80% of prescribed medication. Patients were followed prospectively and evaluated either in clinic or via telephone at 6, 12, and 24 months. The primary outcome was clinical recurrence of ulcerative colitis. Proportional hazards models were used to adjust for confounders.
Results: At 6 months, 12 patients (12%) had clinical recurrence of disease symptoms, all of whom were nonadherent with medication. At 12 months, 19 of 86 patients had recurrent disease, 13 (68%) of whom were nonadherent. Patients who were not adherent with medication had more than a fivefold greater risk of recurrence than adherent patients (hazard ratio = 5.5; 95% confidence interval: 2.3 to 13; P < 0.001).
Conclusion: Nonadherence with medication increases the risk of clinical relapse among patients with quiescent ulcerative colitis. Future research should be directed at behavioral interventions to improve adherence.