Cutoffs to Identify Restricted Life-space Mobility in Older Adults Across Different Contexts: The International Mobility in Aging Study

Abstract

different populations have different averages of life-space assessment scores and defining cutoff values of clinical significance by each population should take into consideration. Different cutoffs to define restricted life space have been reported. The most common is a score of 60 points. There are other cutoffs derived from receiver operating characteristic (ROC) analysis and used to classify older adults according to their ability in activities of daily living (ADLs) (52.3 points) or instrumental activities of daily living (IADLs) (56 points); other cutoffs are specialized for people with cognitive impairment (26.75 points) or people with spinal cord injury who need mobility aids (78.5 points). The aims were to identify cutoff points of Life Space Assessment (LSA) in older adults in different sites and to determine the relationship of the cutoff scores with mobility disability and depression. The study population was composed of community-dwelling adults aged 65–74 years who were not institutionalized. An ROC analysis was constructed, and the area under the curve (AUC) was calculated to identify the optimal cutoff that discriminates life-space restriction for each city. Logistic regressions were executed by site to comprehend the association among restricted LSA and mobility disability and depression. In total, 1890 participants were included in the analyses (52.38% women, 37.19% mobility disability and 21.32% had depression). Canada cities had the highest cutoff, while Tirana and Natal had the lowest cutoff (< 50). Kingston was the site with the highest association between life-space restriction and mobility disability (OR 5.4, 95% CI 2.9–10). Saint-Hyacinthe, Tirana, and Manizales had significant associations between depression and restricted life space (OR 3.25, 95% CI 1.53–6.89, OR 3.14, 95% CI 1.88–5.24, and OR 3.99, 95% CI 2.28–6.98, respectively). Different cutoffs to define restricted life-space have been identified in elderly people at different sites. The analysis of the relationship between the restricted life space and personal characteristics like depression and mobility disability supported these findings. The groupings produced by the cutoff points for each site showed notable variations. These findings emphasize the importance of population-based cutoffs to improve the general applicability of LSM criteria and take into consideration the importance of site-specific approaches.