An economic model of Parkinson's disease: implications for slowing progression in the United States.

Multiple studies describe progression, dementia rates, direct and indirect costs, and health utility by Hoehn and Yahr (H&Y) stage, but research has not incorporated these data into a model to evaluate possible economic consequences of slowing progression. This study aimed to model the course of Parkinson's disease (PD) and describe the economic consequences of slower rates of progression. A Markov model was developed to show the net monetary benefits of slower rates of progression. Four scenarios assuming hypothetical slower rates of progression were compared to a base case scenario. A systematic literature review identified published longitudinal H&Y progression rates. Direct and indirect excess costs (i.e., healthcare costs beyond what similar patients without PD would incur), mortality rates, dementia rates, and health utility were derived from the literature. Ten publications (N = 3,318) were used to model longitudinal H&Y progression. Base case results indicate average excess direct costs of $303,754, life-years of 12.8 years and quality-adjusted life-years of 6.96. A scenario where PD progressed 20% slower than the base case resulted in net monetary benefits of $60,657 ($75,891 including lost income) per patient. The net monetary benefit comes from a $37,927 decrease in direct medical costs, 0.45 increase in quality-adjusted life-years, and $15,235 decrease in lost income. The scenario where PD progression was arrested resulted in net monetary benefits of $442,429 per patient. Reducing progression rates could produce significant economic benefit. This benefit is strongly dependent on the degree to which progression is slowed.