Cost-Effectiveness Analyses of Non-Pharmacological and Non-Surgical Interventions in Idiopathic Parkinson's Disease: A Systematic Review

Background: Interest in non-pharmacological/non-surgical interventions to treat Parkinson's disease (PD) has substantially increased. Although a few health-economic studies have been conducted, summary information on the cost-effectiveness is still scarce. Objective: To give an overview of cost-effectiveness analyses (CEA) focusing on non-pharmacological/non-surgical interventions in PD patients. Methods: A systematic literature search was conducted in five databases. Studies were included that provided costeffectiveness analysis (CEA) or cost-utility analysis (CUA) of non-pharmacological/non-surgical interventions in PD patients. Study quality was assessed with the Drummond and CHEERS 2022 checklists, respectively for economic evaluation. Results: N = 9 studies published between 2012-2023 were identified. Most studies undertook a CUA (n n = 5); n = 3 reported a combination of CEA and CUA, and n =1 a pure CEA. Most studies (n n = 6) examined physical exercise. The CEA studies identified additional costs of 170<euro> -660<euro> for the improvement of one single unit of a clinical outcome and savings of 18.40<euro> -22.80<euro> per score gained as measured with established instruments. The four studies that found significant quality of life benefits show large variations in the incremental cost effectiveness ratio (ICER) of 3,220<euro> -214,226<euro> per quality-adjusted life year (QALY); notably interventions were heterogenous regarding content and intensity. Conclusions: Despite increasing numbers of non-pharmacological/non-surgical intervention trials in PD patients, health- economic evaluations are rare. The examined intervention types and health-economic results vary greatly. Together with the heterogeneity of the health-economic studies these factors limit the conclusions that can be drawn. Further research and a standardization of methods is needed to allow decision makers to make meaningful interpretations, and to allocate scarce resources.