Gait Speed and Mobility Disability: Revisiting Meaningful Levels Across Diverse Clinical Populations

Objectives To investigate the heterogeneity of clinically meaningful levels of gait speed relative to self‐reported mobility disability (SR‐MD). Design Five longitudinal studies with older adults in different health states (onset of acute event, presence of chronic condition, sedentary, community living) were used to explore the relationship between gait speed and SR‐MD. Setting Lifestyle Interventions and Independence for Elders Pilot (LIFE‐P), LIFE, Trial of Angiotensin‐Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN), Baltimore Hip Fracture Study (BHS2), Invecchiare in Chianti (InCHIANTI). Participants Individuals aged 65 and older (N=3,540): sedentary, community dwelling (LIFE‐P/LIFE), with hip fracture (BHS2), random population‐based sample (InCHIANTI), high cardiovascular risk (TRAIN). Measurements Usual‐pace gait speed across 3 to 4 m and SR‐MD, defined as inability to walk approximately 1 block or climb 1 flight of stairs. Results The mean gait speed of participants without SR‐MD was greater than 1.0 m/s in InCHIANTI and TRAIN, 0.79 m/s in LIFE‐P/LIFE, and 0.46 m/sec in BHS2. Of individuals with SR‐MD, mean gait speed was 0.08 m/s slower in LIFE‐P/LIFE, 0.19 m/s slower in TRAIN, 0.22 m/s slower in BHS2, and 0.36 m/s slower in InCHIANTI. The optimal gait speed cutpoint for minimizing SR‐MD misclassification rates ranged from 0.3 m/s in BHS2 to 1.0 m/s in TRAIN. In longitudinal analyses, development of SR‐MD was dependent on initial gait speed and change in gait speed (p