Is gait speed a valid measure to predict community ambulation in patients with Parkinson's disease?

OBJECTIVE To investigate the predictive value of gait speed for community walking in Parkinson's disease and to develop a multivariate prediction model for community walking. DESIGN Data from baseline assessments in a randomized clinical trial were used. SUBJECTS A total of 153 patients with Parkinson's disease were included. METHODS Community walking was evaluated using the mobility domain of the Nottingham extended activities of daily living index (NEAI). Patients who scored 3 points on item 1 ("Did you walk around outside?") and item 5 ("Did you cross roads?") were considered community walkers. Gait speed was measured with the 6-m or 10-m timed walking test. Age, gender, marital status, disease duration, disease severity, motor impairment, balance, freezing of gait, fear of falling, previous falls, cognitive function, executive function, fatigue, anxiety and depression were investigated for their contribution to the multivariate model. RESULTS Seventy patients (46%) were classified as community walkers. A gait speed of 0.88 m/s correctly predicted 70% of patients as community walkers. The multivariate model, including gait speed and fear of falling, correctly predicted 78% of patients as community walkers. CONCLUSION Timed walking tests are valid measurements to predict community walking in Parkinson's disease. However, evaluation of community walking should include an assessment of fear of falling.