[Adherence to oral 5-aminosalicylic acid by patients with quiescent ulcerative colitis: a questionnaire survey].

For patients with ulcerative colitis, adherence to 5-aminosalicylic acid (5-ASA) is generally expected to ensure better maintenance of remission. Over the past 2 years, we have conducted a questionnaire survey in our hospital of 120 outpatients with quiescent ulcerative colitis to assess their adherence to oral 5-ASA. Of them, 112 patients responded. The overall adherence rate was 57%; however, the adherence rate for 5-ASA taken once a day was 95%, which was significantly higher than that for 5-ASA taken twice or three times a day (50%; P=0.00044). Univariate analysis revealed that the factors associated with high adherence included the following: type of 5-ASA derivative, intake of fewer drugs being at a time, and once-daily intake of 5-ASA. However, once-daily intake of 5-ASA was the only factor found to have a statistically significant effect using multivariate analysis. The adherence rate improved from 23% to 100% when the prescription for 5-ASA was changed from two or three times daily to once daily (P=0.000054).