A cost-utility analysis of once daily solifenacin compared to tolterodine in the treatment of overactive bladder syndrome

ABSTRACT

Objective: To evaluate the cost-utility of solifenacin, a new generation antimuscarinic, compared with tolterodine in the treatment of overactive bladder syndrome (OAB), from the perspective of the UK National Health Service (NHS).

Research design and methods: A 1-year Markov model was constructed using data from a 12-week, randomised, double-blind study that compared flexible dosing with solifenacin (5 mg and 10 mg) with tolterodine (IR 2 mg bd/ER 4 mg) in adults with OAB. The model incorporated five discrete health states that were based on disease severity (micturitions/day and incontinence episodes/day). A ‘drop out’ state was also used in the model to account for patients that discontinued treatment in the first year. UK-specific costs for drug treatment and pad use as well as utilities were assigned to each health state.

Results: Solifenacin was a less costly and more effective treatment strategy compared with tolterodine. During the course of 1 year, the estimated cost per patient was £509 for patients treated with solifenacin and £526 for those given tolterodine, a cost saving of £17 per patient. Treatment with solifenacin was also associated with a small incremental gain of 0.004 quality-adjusted-life-years (QALYs) over tolterodine. Sensitivity analysis suggests that the incremental cost effectiveness of solifenacin relative to tolterodine does not appear to exceed £30 000/QALY with even large variations in key model parameters.

Conclusion: Flexible dosing with solifenacin is likely to be cost-effective versus tolterodine in the treatment of OAB. Further studies are needed to confirm these results.

Key words: :

• Antimuscarinic
• Cost-effectiveness analysis
• Cost-utility analysis
• Markov model
• Overactive bladder syndrome
• Solifenacin
• Tolterodine

Acknowledgements

Declaration of interest: This study was funded by Astellas Pharma Europe Ltd. All authors are consultants for Astellas, which is the license holder for solifenacin. Isaac Odeyemi and John Bolodeoku are employed by Astellas Pharma Europe Ltd. The authors thank Abacus International for medical writing assistance, which was also funded by Astellas.