Long-term inequalities in health among older Mexican adults: An outcome-wide analysis

The relationship between socioeconomic level and health outcomes in older people has been widely studied, but less information about health inequalities associated with gender and place of residence exists. Also, there is scarce evidence of longitudinal inequalities, particularly in countries from the global south. This study aimed to describe the longitudinal patterns of health inequalities associated with wealth, gender, and residence area among older Mexican adults. We used data from two longitudinal studies in Mexico: The Study on Global AGEing and Adult Health (SAGE) and the Mexican Health and Aging Study (MHAS). Three domains to characterize health inequities were used: wealth, gender, and rurality. We conducted an outcome-wide analysis with nine health indicators assessing older adults' physical and cognitive function. The Slope Index of Inequality and the Relative Index of Inequality were used as inequality measurements. Our results indicate that the greatest inequalities are observed in relation to wealth and gender. Older adults with lower socioeconomic status demonstrated higher rates of depression, sarcopenia, falls, and limitations in both basic and instrumental activities of daily living compared to their wealthier counterparts, with increasing trends in physical functionality over time. Furthermore, women experienced higher rates of depression, sarcopenia, frailty, and physical limitations compared to men. The only significant difference related to rurality was a lower rate of frailty among rural older adults. Longitudinal trajectories revealed an increase in the gap of inequality for various health indicators, especially in terms of wealth and gender. Health inequalities in old age are one of the greatest challenges facing health systems globally. Actions like universal coverage of health services for older people and the empowerment of individuals and their communities to have control over their lives and circumstances must be guaranteed.