Long-term functional ability trajectories and mental health among older people before and after the COVID-19 pandemic onset in Chile.

OBJECTIVES: Despite the advances in understanding the complex association between functional abilities and mental health in old age, studies have overlooked two important aspects. First, traditionally, research has employed cross-sectional designs, measuring limitations at a single time point. Second, most gerontological studies on this field have been conducted before the COVID-19 pandemic onset. This study aims to explore the association between diverse long-term functional ability trajectories across late adulthood and old age, and older people's mental health in Chile, before and after the COVID-19 pandemic onset. METHODS: We use data from the population-representative and longitudinal 'Chilean Social Protection Survey', sequence analysis to reconstruct functional ability trajectory types from 2004 to 2018, and bivariate and multivariate analyses to measure their association with depressive symptoms in early 2020 (N = 891) and late 2020 (N = 672). We analyzed four age groups defined by their age at baseline (2004): people aged 46-50, 51-55, 56-60, and 61-65. RESULTS: Our findings indicate that erratic or equivocal patterns of functional limitations across time (with people transiting back and forth between low and high levels of limitations) show the worst mental health outcomes, both before and after the pandemic onset. Prevalence of people with depression increased after the COVID-19 onset in most groups, being particularly high among those with previous equivocal functional ability trajectories. CONCLUSIONS: The relationship between functional ability trajectories and mental health calls for a new paradigm, moving away from age as the main policy guide, and highlighting the need to adopt strategies to improve population-level functional status as an efficient policy to address the challenges of population aging.

Extending the Analysis of Functional Ability Trajectories to Unexplored National Contexts: The Case of Chile.

OBJECTIVES: Despite the enormous advances in the field, most evidence about functional ability trajectories in old age comes from studies conducted in developed and high-income countries. This research aims to build on these previous advances to examine functional ability trajectories in Chile. METHOD: Drawing on a robust, publicly available 15-year panel data set (2004-2018), and using sequence analysis, we examine functional ability trajectories types among 4 age groups (people aged 46-50, 51-55, 56-60, and 61-64 at baseline). Then, we analyze trajectories' dynamics looking at intraindividual health-declining and health-recovery transitions between functional ability statuses, within each trajectory type. Finally, we assess how multiple baseline individual characteristics predict the likelihood of following a functional ability trajectory type, using multinomial regression models. RESULTS: Across all age groups, an important fraction (between 26% and 50%) reports stable healthy trajectories, and between 10% and 20% follow equivocal-declining trajectories (i.e., exhibiting both health-declining and health-recovery intraindividual transitions), suggesting that age might not be the main source of heterogeneity in functional ability trajectories. Overall, women, lower educated people, nonworking individuals, and people with a higher burden of chronic conditions at baseline are more prevalent among health-declining trajectory types; however, these results are not constant across the age groups analyzed. DISCUSSION: This nationally focused study reinforces the feasibility and usefulness of an in-depth analysis of functional ability trajectories in old age. The study findings can be crucial to define different prevention strategies according to the functional ability path that an individual might follow, especially in countries like Chile that currently navigate the challenges of population aging.