Economic evaluation of ropinirole prolonged release for treatment of Parkinson's disease in the Netherlands.

Background: By using the findings obtained from the PREPARED study, we aimed to estimate the cost effectiveness of ropinirole prolonged release (PR) [Requip-Modutab(®)] in Parkinson's disease (PD) versus ropinirole immediate release (IR). In the PREPARED study, ropinirole PR provided a significantly greater improvement in time spent 'off' than ropinirole IR when used as an add-on to levodopa.

Methods: A health state transition model was developed-based on Hoehn and Yahr (HY) stages in PD-to compare the two treatment strategies. The Markov model included the following treatment-related aspects: (i) rate of disease progression; (ii) rates of dyskinesia; and (iii) medication adherence.

Results: In our approach, the base-case analysis showed a favourable pharmacoeconomic profile of ropinirole PR versus ropinirole IR. In particular, general cost savings were estimated combined with modest gains in quality of life, due to reduced disease progression and lower dyskinesia rates. Sensitivity analyses showed that this result was rather robust for varying parameters deterministically, although cost savings were lost in some instances. In particular, the treatment benefits of lower dyskinesia rates and improved adherence influenced the cost-effectiveness outcome. Nonetheless, the cost effectiveness remained acceptable within the limits that were investigated. Probabilistic sensitivity analysis revealed that the probability of accepting PR over IR exceeded 95 % for all relevant 'willingness-to-pay' thresholds.

Conclusion: The results of our study indicate a high likelihood of ropinirole PR being cost saving or at least being considered cost effective for use in the Netherlands. However, claims included in our model regarding dyskinesia and improved medication adherence should be further supported by data from daily practice.