Pharmacotherapy adherence and costs versus nonpharmacologic management in overactive bladder.

OBJECTIVE: To evaluate adherence with overactive bladder (OAB) pharmacotherapy and compare costs between patients receiving pharmacotherapy versus nonpharmacologic management. STUDY
DESIGN: Retrospective cohort study using anonymous, patient-level data from administrative claims from the PharMetrics database.
METHODS: Patients 18 years of age or older who received an OAB diagnosis or OAB medication prescription from January 1, 2005, through December 31, 2006, were identified. Eligible patients had continuous health plan enrollment from 6 months before to 12 months after the index date (date of first OAB prescription or first OAB diagnosis); exclusion criteria included prior OAB therapy use. Study cohorts were stratified as OAB therapy or nonpharmacologically managed based on evidence of treatment and matched using propensity score methodology. Outcomes included adherence rates with OAB therapy (defined as proportion of days covered [PDC]) and comparative costs of OAB pharmacotherapy versus nonpharmacologic management from a healthcare payer perspective.
RESULTS: Adherence among OAB therapy patients was low, with 14% of patients achieving PDC of 80% or higher and an average PDC of 32%. Unadjusted total costs were approximately 3% higher for OAB therapy versus nonpharmacologically managed patients due to higher pharmacy costs. Conversely, outpatient service and inpatient hospitalization costs were higher for nonpharmacologically managed patients. Results did not change after adjusting for patient characteristics.
CONCLUSION: Results confirm low adherence to OAB pharmacotherapy, with few patients achieving PDC of 80% or higher. Total costs were higher among OAB therapy patients due to higher pharmacy costs, but outpatient and inpatient costs were higher among nonpharmacologically managed patients. Additional research into optimizing pharmacotherapeutic regimens may provide insight into improving treatment adherence.