Two-Year Trajectory of Fall Risk in People With Parkinson Disease: A Latent Class Analysis

Objective: To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson disease (PD). Design: Latent class analysis, specifically growth mixture modeling (GMM), of longitudinal fall risk trajectories. Setting: Assessments were conducted at 1 of 4 universities. Participants: Community-dwelling participants with PD of a longitudinal cohort study who attended at least 2 of 5 assessments over a 2-year follow-up period (N=230). Interventions: Not applicable. Main Outcome Measures: Fall risk trajectory (low, medium, or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6 monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed. Results: The GMM optimally grouped participants into 3 fall risk trajectories that closely mirrored baseline fall risk status (P =.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium fall risk trajectories (P<.001). Fluctuating fall risk (posterior probability <0.8 of belonging to any trajectory) was found in only 22.6% of the sample, most commonly among individuals who were transitioning to PIGD predominance. Conclusions: Regardless of their baseline characteristics, most participants had clear and stable fall risk trajectories over 2 years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD. (C) 2016 by the American Congress of Rehabilitation Medicine