Natural history of falls in a population-based cohort of patients with Parkinson's disease: An 8-year prospective study

Background: Prospective long-term studies of falls in Parkinson's disease (PD) are scarce. Objective: To examine the development of falls over 8 years in a population-based cohort of ambulatory patients with PD, and to investigate predictors of future falls in non-fallers at baseline. Methods: All patients were examined at baseline and after 4 and 8 years, including the UPDRS, MMSE, Montgomery and Aaberg Depression Rating Scale, Functional Comorbidity Index, and a clinical dementia interview. Logistic regression models were applied to investigate baseline risk factors for future falls. A total of 211 patients were included at baseline, whereas 121 and 64 were re-examined at 4 and 8 years, respectively. Results: The prevalence of falls increased from 41% (87 of 211) at baseline to 72% (46 of 64) after 8 years of prospective follow-up (disease duration 16.2 +/- 4.8 years). Forty-seven non-falling patients at baseline completed all study visits, of these 68% (n = 32) changed fall status during follow-up. Predictive variables for current falling after 4 years were rare or occasional freezing of gait (OR 6.6, 95% CI 1.2-36.9), higher levodopa equivalent doses and more severe speech and axial impairment (both OR 13, 95% CI 1.0-1.7) in non-fallers at baseline. Higher baseline age was the only risk factor for current falling after 8 years. Conclusions: Nearly 3/4 of the PD cohort reported falling after 8 years of follow-up. Disease-specific gait and axial impairments were the major risk factors for future falls in non-fallers at baseline. This has implications for patient education and management. (C) 2014 The Authors. Published by Elsevier Ltd.