Stair negotiation time in community-dwelling older adults: normative values and association with functional decline.

Abstract

To establish reference values for stair ascent and descent times in community-dwelling, ambulatory older adults, and to examine their predictive validity for functional decline. Longitudinal cohort study. Mean follow-up time was 1.8 years (maximum, 3.2y; total, 857.9 person-years). Community sample. Adults 70 years and older (N=513; mean age, 80.8 ± 5.1y) without disability or dementia. Not applicable. Time to ascend and descend 3 steps measured at baseline. A 14-point disability scale assessed functional status at baseline and at follow-up interviews every 2 to 3 months. Functional decline was defined as an increase in the disability score by 1 point during the follow-up period. The mean±SD stair ascent and descent times for 3 steps were 2.78 ± 1.49 and 2.83 ± 1.61 seconds, respectively. The proportion of self-reported and objective difficulty was higher with longer stair ascent and descent times (P<.001 for trend for both stair ascent and descent). Of the 472 participants with at least 1 follow-up interview, 315 developed functional decline, with a 12-month cumulative incidence of 56.6% (95% confidence interval [CI], 52.1%-61.3%). The stair negotiation time was a significant predictor of functional decline after adjusting for covariates including gait velocity (adjusted hazard ratio [aHR] per 1-s increase: aHR=1.12 [95% CI, 1.04-1.21] for stair ascent time; aHR=1.15 [95% CI, 1.07-1.24] for stair descent time). Stair descent time was a significant predictor of functional decline among relatively high functioning older adults reporting no difficulty in stair negotiation (P=.001). The stair ascent and descent times are simple, quick, and valid clinical measures for assessing the risk of functional decline in community-dwelling older adults including high-functioning individuals.