Systematic Review of the Cost of Illness of Parkinson's Disease from a Societal Perspective.

Previous reviews on the cost of illness (COI) of Parkinson's disease (PD) have often focused on health-care costs due to PD, underestimating its effects on other sectors. This systematic review determines the COI of PD from a societal perspective. The protocol was registered in PROSPERO (ID: CRD42023428937). Embase, Medline, and EconLit were searched up to October 12, 2023, for studies determining the COI of PD from a societal perspective. From 2812 abstracts, 17 studies were included. The COI of PD averaged €20,911.37 per patient per year, increasing to almost €100,000 in the most severely affected patients. Health-care costs accounted for 46.1% of total costs, followed by productivity loss (37.4%) and costs to patient and family (16.4%). The COI of PD strongly varied between different geographical regions, with costs in North America 3.6 times higher compared to Asia. This study is the first to identify the relative importance of different cost items. Most important were reduced employment, government benefits, informal care, medication, nursing homes, and hospital admission. There was strong variety in the cost items that were included, with 55.2% of cost items measured in fewer than half of articles. Our review shows that PD-COI is high and appears in various cost sectors, with strong variety in the cost items included in different studies. Therefore, a guideline for the measurement of COI in PD should be developed to harmonize this. This article provides a first step toward the development of such a tool by identifying which cost items are most relevant. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.