Running headline: LSA to identify risk for ADL disability 2 Identification of older people at risk of ADL disability using the Life-Space Assessmenta longitudinal cohort study 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 cut-off scores for baseline LSA and LSA change over time identifying individuals who developed ADL inability during two years of follow-up. Robustness of the cut-off 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 two years later.Participants. Seven-hundred-fifty-five community-dwelling 75-90-years-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 cut-off 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 cut-off points may help to find clinical applications for the LSA.