Direct costs and survival of medicare beneficiaries with early and advanced Parkinson's disease

Abstract

Background: No recent analysis details Parkinson's Disease (PD) costs or survival for Medicare beneficiaries. This study assesses excess direct costs and survival in Medicare beneficiaries with early and advanced PD.

Methods: Patients with ≥ 2 PD diagnoses (ICD-9-CM: 332.0), ≥ age 65, continuously enrolled in Parts A&B during one-year baseline and study periods were selected from the Medicare 5% sample (N = 3.2 million, 1999-2008). Newly diagnosed patients were defined as having no baseline claims for movement disorder, dementia, Alzheimer's, bipolar disorder, psychosis, falls or related injuries, ambulatory assistance device (walker or wheelchair), or skilled nursing facility. Controls without PD were demographically matched 1:1. Costs to Medicare were compared via Wilcoxon rank-sum tests and inverse probability weighted multivariate regression. Survival was assessed via Cox proportional hazards analysis.

Results: Costs in the year post-diagnosis were higher for newly diagnosed patients (N = 9,201, $7423) than controls ($5024), resulting in excess PD-associated costs of $2399 (p < 0.001). Cumulative excess costs were $28,422 from the year prior to index quarter to five years following (p < 0.01). PD patients receiving their first claim for an ambulatory assistance device (N = 11,294) had excess cumulative costs of $50,923 (p < 0.001) over the same period; those receiving their first claim for a skilled nursing facility (N = 10,152) had excess costs of $102,750 (p < 0.001). Hazard rates of mortality were higher among newly diagnosed PD (1.43, p < 0.001), ambulatory assistance device (2.37, p < 0.001) and skilled nursing facility (3.34, p < 0.001) cohorts than in corresponding non-PD groups.

Conclusions: Medicare beneficiaries with PD have substantially and progressively higher costs and mortality compared with controls.