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.