OBJECTIVES: 1) To explore one-year persistence pattern of Overactive Bladder/Urinary Incontinence (OAB/UI) medication treatment; 2) to discover factors associated with persistence; and 3) to investigate the benefit of refill adherence on urinary track infection (UTI). METHODS: Retrospective analyses on continuously enrolled adult patients diagnosed with OAB/UI and received at least one OAB/UI medication from July 1999 to April 2001 (with 6-month run-in period and one-year follow-up period) are employed. Time to discontinuity, defined as the period from the index date to the discontinuity date (when any medication-uncovered interval is longer than 30 days), is used to describe the persistence pattern of patients. Adherence is measured by medication possession ratio (MPR). A Cox Proportional Hazard model is applied to reveal risk factors of non-persistence. A logistic regression is used to examine the relationship of those same factors with refill adherence and to assess the effect of adherence on UTI incidence rate. RESULTS: Of 6518 eligible patients, 26.8% have only 1 prescription. 5751 patients (88.2%) discontinue within the following year, among which, 92.2% fail to continue treatment after 183 days. Only 952 patients (14.6%) exhibit good adherence (MPR>=0.8). The mean MPR of the whole cohort is 0.39 and the median is 0.24. Significant predictors of higher persistence include caucasians, 75 years old or above, prior medication use, and initiating extended-release form of drug. Patients with prior prescription of antidepressant or diagnosis of depression show lower persistence. Similar results are found for adherence. Logistic regression indicates that good refill adherence reduces the risk of being diagnosed with UTI by 33% in the post-treatment period (P=0.0008, OR=0.672). CONCLUSIONS: Both persistence of OAB/UI medication and refill adherence are low, suggesting the need to develop effective interventions in OAB/UI and UTI.