The impact of comorbid disease and injuries on resource use and expenditures in parkinsonism.

BACKGROUND: Persons with parkinsonism have high rates of both associated and unrelated prevalent comorbid conditions. A better understanding of patterns of care and expenditures may aid in designing programs to enhance functioning, lengthen independent living, and manage costs.
METHODS: The authors linked national survey data of 24,831 elderly to nearly 1.9 million Medicare claims. Persons with parkinsonism (n = 791) were identified from survey or Medicare encounters for paralysis agitans. Comorbid disease risk was measured using age-adjusted OR with 95% CI. Comorbidity cost ratios (ratio of average per person per year charges for parkinsonism alone vs with comorbid conditions) were developed to describe incremental costs of comorbidities.
RESULTS: Patients with parkinsonism were older (78.5 +/- 7.6 vs 75.1 +/- 8.3 years, p < 0.0001) and had more injuries resulting in broken bones (35.6% vs 19.5%, p < 0.0001), including broken hips (15.9% vs 5.8%, p < 0.0001), during the 5-year study. Broken hips were more prevalent among men (OR 3.4, 95% CI 2.5 to 4.8) and women (OR 2.5, 95% CI 2.1 to 3.1) with than without parkinsonism. Among those with parkinsonism, comorbidity cost ratios demonstrated two- to threefold higher charges for dementia, broken bones, broken hip, and diabetes.
CONCLUSIONS: Comorbidity associated with parkinsonism is an under-recognized contribution to higher resource use and expenditures. Further study of injuries, dementia, and diabetes is required to assess whether public health interventions could reduce excess morbidity and expenditures associated with parkinsonism.