Dynamics of change in self-reported disability among persons with Parkinson's disease after 2 years of follow-up.

Symptoms of Parkinson's disease (PD) progress over time causing significant disability. Yet, change in disability over shorter time periods has not been entirely understood. The purpose of this study was to assess the Self-Assessment Disability Scale (SADS) in persons with Parkinson's disease (PD) after 2 years of follow-up and compare it with the score observed at baseline. Additionally, we aimed at evaluating association of motor and non-motor PD features at baseline with a higher disability after 2 years of follow-up. A total of 120 consecutive persons with PD, who denied falling in the past 6 months, were initially recruited. After 2 years of follow-up, 88 (73.3%) persons with PD were evaluated for SADS. The total disability (SADS) score did not change after follow-up (p = 0.529). We observed increase in difficulty at "Getting out of bed" (p = 0.006), "Getting up out of armchair" (p = 0.013), "Walking about house/flat" (p = 0.003), "Walking outside" (p = 0.010), and "Traveling by public transport" (p = 0.014). After adjusting for several potential confounding factors, falls in the past year (β = 8.32, 95% confidence interval (CI) 1.04-15.59) and higher Unified Parkinson's Disease Rating Scale part 3 at baseline (β = 0.26, 95%CI 0.01-0.51) remained associated with higher PD-related disability. This finding suggests that accumulation of overall PD-related disability tends to occur over a longer time span. Further studies are needed to gradually assess long-term evolution of disability in PD.