Prospective Questionnaire Survey on Adherence to Oral 5‐Aminosalicylic Acid in Patients With Ulcerative Colitis

Background Adherence to 5‐aminosalicylic acid (5‐ASA), an anchor drug for ulcerative colitis (UC), affects remission maintenance. This study aimed to investigate the current status of adherence to 5‐ASA and identify the factors associated with adherence. Methods We enrolled UC patients whose primary maintenance therapy was oral 5‐ASA at our hospital between January 2017 and December 2018. The adherence status was examined using a questionnaire survey. Various factors, including patient background and disease activity, were also analyzed to identify those related to adherence. A second questionnaire with the same content was performed 1 year after the initial survey for comparison. Results In total, 297 patients with UC answered the first questionnaire, of which 278 answered the second questionnaire. Complete adherence rates at the time of the first and second questionnaires were 49.8% (148/297) and 55.8% (155/278), respectively. Full‐time employment ( p = 0.00893), eating one or two meals per day ( p = 0.00641), and multiple daily doses ( p = 0.0153) were significantly associated with lower adherence. The 119 patients who fully adhered to both the primary and secondary questionnaires had a significantly higher cumulative non‐relapse rate at 1 year than those 159 who were not (85.7% vs. 76.1%, p = 0.0207). Conclusions UC patients with high adherence to 5‐ASA showed a high rate of remission maintenance, so adherence should be improved by considering factors such as the number of medications taken, work status, and dietary habits.