Letter fluency and level of depression predict fear of falling in Parkinson's disease.

Abstract

Objective: Indicators of motor symptom severity, cognitive functioning, and level of depression have been independently associated with fear of falling in Parkinson's disease (PD); however, it is unclear how these variables combine to predict fear of falling and which specific measures of cognition are most related to fear of falling in PD. The goal of this study was to address these questions.

Method: Fifty-eight (27 female) individuals diagnosed with PD completed the Falls Efficacy Scale International (FES), Part III of the Unified Parkinson's Disease Rating Scale, Geriatric Depression Scale, Symbol-Digit Modalities Test, and Trail Making, Verbal Fluency and Color-Word Interference Tests from the Delis-Kaplan Executive Function System. Scores from the motor, cognitive, and depression measures were entered into a standard multiple regression predicting FES scores.

Results: All variables significantly correlated with the FES, with r-values ranging from .26 to .45. In the regression, the independent variables predicted 38.5% of the variance in FES, R2 = .385, F(5, 52) = 7.70, p < .001. Letter Fluency made the largest contribution to FES, β = -.38, t = -2.92, p = .005, with the Geriatric Depression Scale, β = .31, t = 2.48, p = .016 contributing significant additional unique variance in FES.

Conclusions: Fear of falling is a multifactorial construct in PD and appears independently related to elements of executive functioning and level of depression.