Objectives

Life-space mobility, assessed with the Life-Space Assessment (LSA), reflects an individual's mobility in terms of the spatial area, frequency, and need for assistance. The aims were to study associations between life-space mobility and disability status in activities of daily living (ADL), and to define cutoff scores for baseline LSA and LSA change over time identifying individuals who developed ADL inability during 2 years of follow-up. Robustness of the cutoff scores was tested accounting for potential confounders.

Design

Longitudinal analyses of the “Life-space mobility in old age” cohort study.

Setting

Home-based interviews at baseline and phone interviews 2 years later.

Participants

A total of 755 community-dwelling 75- to 90-year-old people living in Central Finland.

Measurements

LSA score (range 0–120) and ADL disability status (no difficulty, difficulty in ≥1 tasks, or inability in ≥1 tasks) were determined based on self-reports.

Results

Participants who developed difficulty or inability in ADL over time presented lower LSA scores at baseline and larger declines compared to those who remained without task difficulty or inability during the follow-up, respectively. Sensitivity and specificity analyses showed that baseline LSA ≤52.3 (0.86 and 0.74, respectively) and LSA decline of >11.7 (0.76 and 0.71, respectively) identified participants who developed ADL inability over the follow-up. Multinomial regression showed that, after adjustment for potential confounders, these cutoff scores increased the odds to develop new difficulty in ADL tasks, and the odds to develop ADL inability among those with baseline difficulty.

Conclusion

Our results suggest that restrictions and declines in life-space mobility may be early signs of increasing vulnerability to disability in old age. These longitudinally defined cutoff points may help to find clinical applications for the LSA.