PREDICTORS OF CHANGE IN WALKING VELOCITY IN OLDER ADULTS

OBJECTIVE: To determine factors that predict change in walking velocit y in older people using a multivariate model. DESIGN: Longitudinal obs ervational study. SUBJECTS: A total of 588 persons older than age 60, including subjects residing in a continuing care retirement community (CCRC) (n = 248), and homebound (n = 79) and ambulatory (n = 261) subj ects. Mean age at baseline = 77. MEASUREMENT: Independent variables in cluded demographics, physician measures of lower-extremity joint impai rment and other musculoskeletal and neurological variables, comorbidit ies derived from physical examination and chart abstract, self-assesse d arthritis pain, depression, and anxiety. The major dependent variabl es were 2- and 4-year decline in walking velocity below a threshold as sociated with nursing home placement. MAIN RESULTS: From baseline to Y ear 4, median walking velocity declined from 61.8 to 53.0 m/min, and t he proportion oi subjects above a threshold value of 11.5 m/min declin ed from 95.3% to 80.4%. Age, joint impairment, and weakness of quadric eps, measured at baseline, predicted 2-year and 4-year decline in walk ing velocity. CONCLUSIONS: The findings indicate that joint impairment and quadriceps strength contribute significantly to crossing a clinic ally significant threshold in walking velocity among older people over time. Future research is needed to determine whether these risk facto rs can be modified through preventive interventions such as muscle-str engthening exercises and pain medication.