The association between non-motor symptoms and cost in Parkinson's disease

Background Parkinson's disease (PD) is a neurodegenerative disorder associated with substantial costs that escalate as the disease progresses. Previous research has explored the relationship between disease progression, motor symptoms, and the economic burden of PD. However, there is a lack of studies focusing on the relationship between costs and non-motor symptoms (NMS). Objective To examine the association between societal costs and NMS in individuals with PD in Sweden. Methods Persons with idiopathic PD in the Swedish Parkinson's disease registry from the region of Skane with registrations of non-motor symptoms questionnaire (NMSQ) were included. Identified subjects were linked to administrative health care data registries, to estimate annual costs. A generalized linear model was used to assess the relationship between NMS and costs. Results NMS were present in 74% (n = 703) of the study population, with a mean of 6.9 symptoms per observation. The number of NMS increased with disease duration, and costs were higher for those with a greater number of symptoms. Formal care costs were 3.8 times higher in observations with at least 10 NMS. Experiencing hallucinations and/or delusions was associated with an 80-94% increase in total costs, corresponding to an additional SEK 107,000-121,000 per patient year. Conclusions Presence of NMS in PD is associated with substantial societal costs. Findings from this study highlight the necessity for comprehensive management strategies that address both motor and non-motor symptoms to potentially alleviate the burden on patients and the healthcare system.