Self-reported walking ability predicts functional mobility performance in frail older adults

OBJECTIVE: To determine how self-reported physical function relates to perf ormance in each of three mobility domains: walking, stance maintenance, and rising from chairs. DESIGN: Cross-sectional analysis of older adults. SETTING: University-based laboratory and community-based congregate housing facilities. PARTICIPANTS: Two hundred twenty-one older adults (mean age, 79.9 years; ra nge, 60-102 years) without clinical evidence of dementia (mean Folstein Min i-Mental State score, 28; range, 24-30). INTERVENTION AND MAIN OUTCOME MEASURES: We compared the responses of these older adults on a questionnaire battery used by the Established Populations for the Epidemiologic Study of the Elderly (EPESE) project, to performance an mobility tasks of graded difficulty. Responses to the EPESE battery inc luded: (1) whether assistance was required to perform seven Katz activities of daily living (ADL) items, specifically with walking and transferring; ( 2) three Rosow-Breslau items, including the ability to walk up stairs and w alk a half mile; and (3) five Nagi items, including difficulty stooping, re aching, and lifting objects. The performance measures included the ability to perform, and time taken to perform, tasks in three summary score domains : (1) walking ("Walking," seven tasks, including walking with an assistive device, turning, stair climbing, tandem walking); (2) stance maintenance (" Stance," six tasks, including unipedal, bipedal, tandem, and maximum lean); and (3) chair rise ("Chair Rise," six tasks, including rising from a varie ty of seat heights with and without the use of hands for assistance). A tot al score combines scores in each Walking, Stance, and Chair Rise domain. We also analyzed how cognitive/behavioral factors such as depression and serf -efficacy related to the residuals from the self-report and performance-bas ed ANOVA models. RESULTS: Rosow-Breslau items have the strongest relationship with the three performance domains, Walking, Stance, and Chair Rise (eta-squared ranging from 0.21 to 0.44). These three performance domains are as strongly related to one Katz ADL item, walking (eta-squared ranging from 0.15 to 0.33) as a ll of the Katz ADL items combined (eta-squared ranging from 0.21 to 0.35). Tests of problem solving and psychomotor speed, the Trails A and Trails B t ests, are significantly correlated with the residuals from the self-report and performance-based ANOVA models. CONCLUSIONS: Compared with the rest of the EPESE self-report items, self-re port items related to walking (such as Katz walking and Rosow-Breslau items ) are better predictors of functional mobility performance on tasks involvi ng walking, stance maintenance, and rising from chairs. Compared with other self-report items, self-reported walking ability may be the best predictor of overall functional mobility.