Determination of the Minimal Important Change in the Life-Space Assessment

Abstract

Background/objectives: The University of Alabama at Birmingham (UAB) Life-Space Assessment (LSA) is a widely used measure of community mobility. To assist clinicians and researchers with assessing the significance of changes in scores, we determined the minimal important change associated with a change in health status.

Setting: Homes of community-dwelling older adults.

Participants: A total of 419 African American and non-Hispanic white adults 75 years and older participating in the UAB Study of Aging II, a longitudinal epidemiological study across the state of Alabama.

Intervention: None.

Measurements: Linear mixed models were used to compare change in LSA scores over 1-month intervals (N = 9712) between participants reporting improvement, no change, or decline in activities of daily living walking scores, accounting for the correlation among scores for the same participant over time.

Results: A decline in walking status was associated with a mean decrease in LSA scores of 2.93 points (95% confidence interval [CI] = 1.69-4.17 points), indicating lower mobility. An improvement in walking status was associated with a mean increase in LSA scores of 2.51 points (95% CI = 1.26-3.77 points), indicating higher mobility.

Conclusion: A change in LSA scores of five or more is clinically important, exceeding the 95% CI for the change in LSA associated with change in walking status. Changes exceeding this threshold should prompt further investigation by providers with a goal of preserving mobility. J Am Geriatr Soc 67:565-569, 2019.

Keywords: activities of daily living; life space; minimal important change; mobility; walking.