Analysis of costs and consequences related to the persistence of Mirabegron and antimuscarinic treatments and their impact on quality of life in patients with overactive bladder in Spain: Results of a probabilistic model.

To evaluate whether the lower dropout rate of the treatment of overactive bladde r(OAB) with mirabegron could generate cost savings to the National Health System (NHS) and lead to quality-adjusted life years (QALYs) gains, compared to the most commonly prescribed antimuscarinics (AM) in Spain (tolterodine, fesoterodine, oxybutynin, solifenacin). A probabilistic model (second order Monte Carlo simulation) in a hypothetical cohort of 1,000 patients with OAB and a time horizon of 1 year was carried out. Discontinuation and persistence rates for both mirabegron and AM were obtained from a Spanish observational study in 1798 patients. Unit costs (€ 2018) and utility loss associated with treatment discontinuation were obtained from Spanish public prices and literature, respectively. Persistence rates in patients treated with mirabegron were twice as high compared to AM, leading to a QALY gain of 0.0151 ± 0.0007 per year. Treatment with mirabegron could generate savings of 80.74 ±4.61 € per patient per year compared to AM, assuming 100% probability of saving. The hypothetical substitution of AM treatment for mirabegron could potentially generate savings of 6.6 million euros (95% CI 3.9-10.1 million euros) to the NHS and 1,238 QALYs gains (CI95%731; 1,885 QALYs) within a period of 1 year. The probabilistic model presented showed a greater persistence in patients treated with mirabegron compared to AM, leading to a positive impactin patients quality of life, as well cost savings to the NHS in Spain.