Cost-effectiveness of pergolide compared to bromocriptine in the treatment of Parkinson's disease: a decision-analytic model.

OBJECTIVE: To develop a decision-analytic model to assess the cost-effectiveness of pergolide versus bromocriptine in the treatment of Parkinson's disease (PD). METHODS: A Markov decision-analytic model is used to examine cost-effectiveness. The model ran for 20 cycles of 6 months' duration, and the patients progress through six stages: Hoehn-Yahr stages 1-5 and death. The transitional probabilities for each stage are derived from a 12-year longitudinal study of patients with PD. The costs in the model are derived from an expert panel containing six Australian neurologists. A review of the randomized controlled trials comparing the efficacy and safety of pergolide versus bromocriptine was undertaken. Five studies were identified, with four showing that pergolide offers superior efficacy when compared to bromocriptine. The Mizuno et al. (1995) study was the largest of the controlled trials and also measured patient Hoehn-Yahr status before and after treatment. This was identified as the most appropriate source of relative efficacy data for the model. The model examined various scenarios based on alternate durations of superior clinical benefit with pergolide compared to bromocriptine. The main analysis assumed that patients in each arm of the model would have identical Hoehn-Yahr status by the fifth year. Sensitivity analysis was used to determine cost-effectiveness in the case where the therapeutic benefit was of a shorter duration. RESULTS: The Mizuno study indicates that an additional 19.09% of patients improved by at least one stage on pergolide over bromocriptine, with an odds ratio of 2.26 (p < .01). The total health care cost per patient over the 10-year period was $46,323 in the pergolide treatment arm and $47,351 in the bromocriptine treatment arm, an incremental saving of $1028. Patients also spent extra time in Hoehn-Yahr stages 1, 2, and 3. In sensitivity analyses, when the benefit from pergolide expired between 6 months and 5 years after treatment cessation, cost savings ranged from $68 to $2535. CONCLUSION: Pergolide is cost saving and more efficacious than bromocriptine, and is therefore cost-effective.

Cost-effectiveness analysis of dopamine agonists in the treatment of Parkinson's disease in Japan.

BACKGROUND: Dopamine agonists such as bromocriptine or pergolide are often used in Japan to treat Parkinson's disease. Dopamine agonists are relatively expensive drugs; economic evaluations are required. OBJECTIVE: To evaluate the cost effectiveness of dopamine agonists for the treatment of Parkinson's disease in Japan. DESIGN AND SETTING: We used a Markov model to simulate the course of Parkinson's disease and to compare the cost effectiveness of dopamine agonists added to levodopa with that of levodopa alone in Japan. The model assumed that 60-year-old men with Parkinson's disease in Hoehn-Yahr (HY) stages 2 to 5 using levodopa were administered dopamine agonists or continued on levodopa alone. The incremental cost effectiveness of dopamine agonists used for 10 years was then estimated. STUDY PERSPECTIVE: Societal. MAIN OUTCOME MEASURES AND RESULTS: In the patients in HY stage 2, the incremental cost effectiveness of dopamine agonists was 18,610,000 to 19,320,000 yen per quality-adjusted life-year (QALY) [$US 172,300 to $US 178,900/QALY; 1998 values] . In patients in HY stage 3 or higher, the use of dopamine agonists was dominant over levodopa alone mainly due to reduced cost for care. In sensitivity analyses, costs and effectiveness of dopamine agonists significantly influenced the results. The use of a generic formulation of bromocriptine was dominant over levodopa alone even in the patients with HY stage 2 disease. CONCLUSIONS: Dopamine agonists appear to be cost effective in advanced Parkinson's disease, although their use is sensitive to the costs and effectiveness of dopamine agonists. If factors discouraging the prescription of generic drugs in Japan were removed, the treatment of Parkinson's disease would become more cost effective.