36‐Item Short Form Survey (SF‐36) Versus Gait Speed As Predictor of Preclinical Mobility Disability in Older Women: The Women's Health Initiative

Objectives To compare the value of clinically measured gait speed with that of the self‐reported Medical Outcomes Study 36‐item Short‐Form Survey Physical Function Index (SF‐36 PF) in predicting future preclinical mobility disability (PCMD) in older women. Design Prospective cohort study. Setting Forty clinical centers in the United States. Participants Women aged 65 to 79 enrolled in the Women's Health Initiative Clinical Trials with gait speed and SF‐36 assessed at baseline (1993–1998) and follow‐up Years 1, 3, and 6 (N = 3,587). Measurements Women were categorized as nondecliners or decliners based on changes (from baseline to Year 1) in gait speed and SF‐36 PF scores. Logistic regression models were used to estimate incident PCMD (gait speed