Assessing mobility in older adults: The UAB Study of Aging Life-Space Assessment

Background and Purpose. The University of Alabama at Birmingham (UAB) Study of Aging Life-Space Assessment (LSA) is a relatively new instrument to measure mobility. The purpose of this report is to describe the relationships between LSA and traditional measures of physical function, sociodemographic characteristics, depression, and cognitive status. Subjects. Subjects were a stratified random sample of 998 Medicare beneficiaries aged ≥65 years. The sample was 50% African American, 50% male, and 50% from rural (versus urban) counties. Methods. In-home interviews were conducted. Mobility was measured using the LSA, which documents where and how often subjects travel and any assistance needed during the 4 weeks prior to the assessment. Basic activities of daily living (ADL) and instrumental activities of daily living (IADL), cognitive status, income level, presence of depressive symptoms, and transportation resources were determined. The Short Physical Performance Battery (SPPB) was used to assess physical performance. Results. Simple bivariate correlations indicated a significant relationship between LSA and all variables except residence (rural versus urban). In a regression model, physical function (ADL, IADL) and physical performance (SPPB) accounted for 45.5% of the variance in LSA scores. An additional 12.7% of the variance was explained by sociodemographic variables, and less than 1% was explained by cognition and depressive symptoms. Discussion and Conclusion. The LSA can be used to document patients' mobility within their home and community. The LSA scores are associated with a person's physical capacity and other factors that may limit mobility. These scores can be used in combination with other tests and measures to generate clinical hypotheses to explain mobility deficits and to plan appropriate interventions to address these deficits.