Predictors of persistence with 5‐aminosalicylic acid therapy for ulcerative colitis

BACKGROUND: Individuals with ulcerative colitis (UC) are at risk for poor persistence with therapy. AIM: To identify factors predicting persistence with 5-aminosalicylic acid (5-ASA) therapy after 3 and 12 months in subjects with UC. METHODS: In this retrospective cohort study, persistence with 5-ASA therapy was determined from prescription refill data from a commercial health insurance claims database. The analysis included subjects with UC who filled a prescription for any oral 5-ASA between October 2002 and September 2004. Persistence was defined as prescription refill at 3 and/or 12 months. Multivariate logistic regression modelling identified variables independently associated with persistence at 3 and 12 months. RESULTS: In all, 3574 subjects were identified. Fifty-seven per cent (2044) were persistent at 3 months. Glucocorticoid use before the index prescription predicted improved persistence at 3 months. Psychiatric diagnosis, mail order of the index prescription, female gender and co-pay predicted decreased persistence. At 12 months, 1124 (55%) remained persistent. Rectal 5-ASA use, older age and switching to a different 5-ASA predicted improved persistence at 12 months. Hospitalization for a gastrointestinal condition, mail order of the 3-month prescription and number of co-morbid illnesses predicted lower persistence. CONCLUSION: Persistence with 5-ASA treatment in UC is complex and multifactorial, and differs by time period.