Cost analysis of ropinirole versus levodopa in the treatment of Parkinson's disease.
BACKGROUND
Not all patients with Parkinson's disease (PD) respond to levodopa and others develop dyskinesias. Ropinirole, a dopamine agonist, is associated with fewer dyskinesias than levodopa.


OBJECTIVE
To examine the economic impact of reducing dyskinesias using ropinirole instead of levodopa plus benserazide in PD was examined. The research question addressed was: is the added cost of ropinirole offset by savings due to avoided cases of dyskinesia?


METHODS
A cost-minimisation analysis was performed from both the societal and Ministry of Health (MoH) of Ontario, Canada perspectives, using 5-year data from a study of dyskinesia outcomes comparing ropinirole with levodopa plus benserazide. A predictive model was developed to capture resource utilisation over 5 years, such as medication costs, medical consultations, hospital admissions, nursing home admissions, caregiver time and productivity loss. The model was based on a previously reported clinical trial which determined dyskinesia rates to be 20% for ropinirole and 45% for levodopa. Standard costing lists were used, and costs were discounted at various rates. Constant 1999 Canadian dollars ($Can) were applied, and no increases were assumed over the time horizon of the analysis. A multivariate sensitivity analysis with changes in key parameters was also performed.


RESULTS
From a societal perspective, ropinirole was cost saving. From the MoH perspective, the analysis yielded an incremental expected daily cost/patient of $Can4.41 for substituting levodopa plus benserazide with ropinirole. Ropinirole resulted in daily savings/patient of $Can0.17 in non-drug healthcare costs. In the sensitivity analysis, the direction of results did not change despite changes of 15 to 20% in key parameters, suggesting robustness of the model.


CONCLUSIONS
From the societal perspective, in comparison with levodopa plus benserazide, the added cost of ropinirole is offset by savings due to avoided cases of dyskinesia.
Iskedjian
Michael
M
PharmIdeas Research & Consulting Inc., Oakville, Ontario, Canada. skedji@pharmideas.com
Einarson
Thomas R
TR
D000328:Adult; D000978:Antiparkinson Agents / Q000191:economics* / Q000627:therapeutic use; D001545:Benserazide / Q000191:economics / Q000627:therapeutic use; D002170:Canada; D017028:Caregivers / Q000191:economics; D017046:Cost Savings; D018491:Dopamine Agonists / Q000191:economics* / Q000627:therapeutic use; D016527:Drug Costs; D017048:Health Care Costs; D006801:Humans; D007211:Indoles / Q000191:economics* / Q000627:therapeutic use; D007980:Levodopa / Q000191:economics* / Q000627:therapeutic use; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000191:economics*; D016896:Treatment Outcome
D000978:Antiparkinson Agents; D018491:Dopamine Agonists; D007211:Indoles; C046649:ropinirole; D007980:Levodopa; D001545:Benserazide