Net Health System Costs of Parkinson Disease: A Propensity Score-Matched Health Administrative Data Cohort Study in Ontario, Canada.

Background and Objectives: Few estimates of the long-term health system costs of Parkinson disease by phase of disease are available. We estimated 10-year and phase-based net health system costs of Parkinson disease before and after case ascertainment. Methods: Using population-based linked administrative databases from Ontario, Canada, we identified 43,149 community-dwelling persons with incident Parkinson disease aged 40 years and older between 2009 and 2018 using a validated algorithm. These individuals were matched 1:1 to controls without Parkinson disease based on demographics and a propensity score. We calculated phase-based, net health system costs from the provincial government perspective during the preascertainment (3 years before index), initial (1 year after index), early continuing (>1-6 years after index), later continuing (>6-10 years after index), and terminal (1 year before death, if applicable) phases (standardized to 2020 $CAD and calculated on an annual basis). By applying survival probabilities to monthly cost estimates, we also determined 10-year net health system costs, stratified by sex and age. Results: Annual mean net costs of Parkinson disease were lowest in the preascertainment phase ($212 CAD, 95% CI [$20-$404]), intermediate in the initial phase ($4,576 (95% CI [$4,217-$4,935]), and higher in the early continuing phase ($7,078, 95% CI [$6,717-$7,438]). The later continuing phase ($12,500, 95% CI [$12,060-$12,940]) and the terminal phase ($13,933, 95% CI [$13,123-$14,743]) showed the highest costs. The 10-year net cost of Parkinson disease was $82,153 (95% CI [$77,965-$86,341]) and was significantly higher in women ($89,773, 95% CI [$83,306-$96,240]) than in men ($76,469, 95% CI [$70,983-$81,953]) and older individuals ($92,197, 95% CI [$87,087-$97,307]), compared with younger individuals ($62,580, 95% CI [$55,346-$69,814]). Over the 10-year period, hospital, nursing home, and home care were the largest contributors to costs of Parkinson disease. Discussion: Health system costs of Parkinson disease are substantial, particularly in the later phases. Interventions to reduce avoidable use of hospital and nursing home services by persons living with Parkinson disease may provide better quality of life and be cost saving from the health system perspective.