Validity of measures for life space mobility and physical activity in older adults with lower-limb amputation.

BACKGROUND Older adults with lower-limb amputations (LLAs) often experience lack of confidence and poor balance, which limits their mobility. There are few validated measures for assessing these outcomes in the LLA population. OBJECTIVES To assess the validity of the Life Space Assessment (LSA) and the Physical Activity Scale for the Elderly (PASE) for older adults with LLA. STUDY DESIGN Secondary analyses of cross-sectional data. METHODS Sixty-eight older adults with LLA across Canada were recruited to complete the LSA and the PASE. Validity was assessed via correlations with the Activities-specific Balance Confidence (ABC), Four-Square Step Test (FSST), and Two-Minute Walk Test (2-MWT). RESULTS As hypothesized, the LSA was positively correlated with the ABC (ρ = 0.36, 95% confidence interval [CI] [0.17, 0.62]) and 2-MWT (r = 0.49, 95% CI [0.27, 0.70]) and negatively correlated with FSST (ρ = -0.39, 95% CI [-0.56, -0.10]). The PASE was positively correlated with the ABC (ρ = 0.34, 95% CI [0.10, 0.56]) and 2-MWT (ρ = 0.32, 95% CI [0.05, 0.52]), and negatively correlated with FSST (ρ = -0.36, 95% CI [-0.53, -0.07]). CONCLUSIONS The LSA has validity in measuring life space mobility. The PASE captures the physical activity with weaker support of validity in older adults with LLA. CLINICAL RELEVANCE The LSA and PASE are quick low-cost tools for clinicians to assess mobility-related functional health and physical activity, respectively, in older adults with LLA. However, the PASE may contain activities that are not common among older adults with LLA.