Relative mortality in U.S. Medicare beneficiaries with Parkinson disease and hip and pelvic fractures.

BACKGROUND Parkinson disease is a neurodegenerative disease that affects gait and postural stability, resulting in an increased risk of falling. The purpose of this study was to estimate mortality associated with demographic factors after hip or pelvic (hip/pelvic) fracture in people with Parkinson disease. A secondary goal was to compare the mortality associated with Parkinson disease to that associated with other common medical conditions in patients with hip/pelvic fracture. METHODS This was a retrospective observational cohort study of 1,980,401 elderly Medicare beneficiaries diagnosed with hip/pelvic fracture from 2000 to 2005 who were identified with use of the Beneficiary Annual Summary File. The race/ethnicity distribution of the sample was white (93.2%), black (3.8%), Hispanic (1.2%), and Asian (0.6%). Individuals with Parkinson disease (131,215) were identified with use of outpatient and carrier claims. Cox proportional hazards models were used to estimate the risk of death associated with demographic and clinical variables and to compare mortality after hip/pelvic fracture between patients with Parkinson disease and those with other medical conditions associated with high mortality after hip/pelvic fracture, after adjustment for race/ethnicity, sex, age, and modified Charlson comorbidity score. RESULTS Among those with Parkinson disease, women had lower mortality after hip/pelvic fracture than men (adjusted hazard ratio [HR] = 0.63, 95% confidence interval [CI]) = 0.62 to 0.64), after adjustment for covariates. Compared with whites, blacks had a higher (HR = 1.12, 95% CI = 1.09 to 1.16) and Hispanics had a lower (HR = 0.87, 95% CI = 0.81 to 0.95) mortality, after adjustment for covariates. Overall, the adjusted mortality rate after hip/pelvic fracture in individuals with Parkinson disease (HR = 2.41, 95% CI = 2.37 to 2.46) was substantially elevated compared with those without the disease, a finding similar to the increased mortality associated with a diagnosis of dementia (HR = 2.73, 95% CI = 2.68 to 2.79), kidney disease (HR = 2.66, 95% CI = 2.60 to 2.72), and chronic obstructive pulmonary disease (HR = 2.48, 95% CI = 2.43 to 2.53). CONCLUSIONS Mortality after hip/pelvic fracture in Parkinson disease varies according to demographic factors. Mortality after hip/pelvic fracture is substantially increased among those with Parkinson disease.