Long-term benefits of darifenacin treatment for patient quality of life: Results from a 2-year extension study

Background and Aims: Overactive bladder (OAB), a chronic condition requiring long-term management, is associated with substantial impact on health-related quality of life (HRQoL). The short-term benefits of antimuscarinic drug treatment are well known. Here we investigate the impact on HRQoL of long-term treatment with the M-3-selective muscarinic receptor antagonist darifenacin over 2 years. Methods: HRQoL was assessed using the King's Health Questionnaire (KHQ) for patients with 'wet' OAB treated with darifenacin (7.5/15 mg once daily [o.d.]) in an open-label 2-year extension of two double-blind feeder studies. Data were also analyzed for the subset of patients who continued darifenacin 7.5/15 mg o.d. directly into the extension study from the feeder studies (the 'darifenacin continuation' group), and also older patients (>= 65 years) and men within this group. Results: The total study population comprised 716 patients, of whom 303 patients formed the 'darifenacin continuation' group (including 85 patients >= 65 years and 41 men). Substantial impairment of HRQoL was noted in baseline KHQ assessments. KHQ scores improved significantly from feeder-study baseline to extension study end/last visit in eight of the nine domains, with more than 50% of patients reporting improvements in seven of the nine domains. Despite fewer patients, significant improvements in KHQ scores were also observed in the subsets of older patients (>= 65 years) and men. Almost two-thirds of the 'darifenacin continuation' group were either satisfied or extremely satisfied with treatment. Conclusions: Long-term darifenacin treatment was associated with significant and clinically meaningful improvements in HRQoL for patients with 'wet' OAB over 2 years.