Reference Ranges for Gait Speed and Sit-to-Stand Performance in a Cohort of Mobility-Intact Community-Dwelling Older Adults From Singapore.

Abstract

Slow gait speed and sit-to-stand performance are associated with adverse clinical outcomes in older adults. Identifying older adults with functional performance "below norms" is the first step toward prevention. We aimed to (1) examine the associations of age, body height, and gender with gait speed and sit-to-stand performance and (2) develop subgroup-specific reference ranges in older adults with no self-reported mobility limitations. Cross-sectional study. This study analyzed data from 775 community-dwelling older adults who reported no difficulty walking 100m, climbing stairs, and rising from the chair. Gait speed and sit-to-stand performance were measured by the 10-m gait speed test and 5-times sit-to-stand test, respectively. Bayesian linear regression was used to derive 95% reference ranges for gait speed and sit-to-stand performance, defined by different levels of age, body height, and gender. Overall, 95% reference range was 0.89-1.79m/s for habitual gait speed and 7.4-27.9 stands/30s for sit-to-stand pace. Age had the highest posterior probability (>99%) of a meaningful association with both functional outcomes. Additionally, height was strongly associated with gait speed: a 10-cm increase in height was associated with 0.07m/s (95% credible interval, 0.05-0.10) faster gait speed. For sit-to-stand test, the lower 95% reference range limits tended to be similar across gender and gender-specific height subgroups, owing to the associations of faster sit-to-stand pace with shorter height and male gender. Because extensive tables of reference ranges are impractical, a web-based application (https://sghpt.shinyapps.io/ippts/) is created to provide subgroup-specific reference ranges. In a large sample of mobile-intact older adults, reference ranges for gait speed and sit-to-stand performance differed meaningfully by age. Furthermore, gait speed was stature dependent. Although requiring validation, our findings may be used to define subgroup-specific "below-range" values and to complement existing universal clinical cut points for gait speed and sit-to-stand performance.