Disability is an Independent Predictor of Falls and Recurrent Falls in People with Parkinson's Disease Without a History of Falls: A One-Year Prospective Study

Background: Predictors of falls in people with Parkinson's disease (PD) who have not previously fallen are yet to be identified. Objectives: We aimed to identify predictors of all falls and recurrent falls in people with PD who had not fallen in the previous year and to explore the timing of falls in a 12-month follow-up period. Methods: Participants with PD(n = 130) were assessed by disease-specific, self-report and balance measures. Falls were recorded prospectively for 12 months. Univariate and multivariate analyses were performed. Kaplan-Meier survival analysis was used to investigate time to falling. Results: Forty participants (31%) had >= 1 fall during follow-up and 21 (16%) had >= 2 falls. Disability, reduced balance confidence and greater concern about falling were associated with >= 1 fall in univariate analyses. Additionally, PD duration and severity, freezing of gait and impaired balance were associated with >= 2 falls (p < 0.05). Disability (Schwab and England scale, Odds Ratio [OR] = 0.56 per 10 points increase; 95% confidence interval [CI] 0.39-0.80; p = 0.002) was associated with >= 1 fall in the final multivariate model (area under the receiver operating characteristic curve [AUC] = 0.65; 95% CI 0.55-0.76; p = 0.005). Disability (Unified Parkinson's Disease Rating Scale activities of daily living, OR = 1.20; 95% CI 1.07-1.34; p = 0.001) and levodopa equivalent dose (OR = 1.11 per 100 mg increase; 95% CI 0.95-1.30; p = 0.19) were associated with >= 2 falls in the final multivariate model (AUC = 0.72; 95% CI 0.60-0.84; p = 0.001). Recurrent fallers experienced their first fall earlier than single fallers (p < 0.05). Conclusions: Self-reported disability was the strongest single predictor of all falls and recurrent falls.