Original article The cost-effectiveness of solifenacin vs. trospium in the treatment of patients with overactive bladder in the German National Health Service

Objective: To carry out a cost–utility analysis comparing initial treatment of patients with overactive bladder (OAB) with solifenacin 5mg/day versus either trospium 20mg twice a day or trospium 60mg/day from the perspective of the German National Health Service. Methods: Adecision analytic modelwith a3 monthcyclewas developed to followacohortof OABpatients treated with either solifenacin or trospium during a 1 year period. Costs and utilities were accumulated as patients transitioned through the four cycles inthe model. Some of the solifenacin patients were titrated from 5mg to 10mg/day at 3 months. Utility values were obtained from the published literature and pad use was based on a US resource utilization study. Adherence rates for individual treatments were derived from a United Kingdom general practitioner database review. The change in the mean number of urgency urinary incontinence episodes/day from after 12 weeks was the main outcome measure. Baseline effectiveness values for solifenacin and trospium were calculated using the Poisson distribution. Patients who failed second-line therapy were referred to a specialist visit. Results were expressed in terms of incremental cost– utility ratios.