Inequalities in disability-free and disabling multimorbid life expectancy in Costa Rica, Mexico, and the United States

Existing research on multimorbidity (two or more co-existing chronic diseases) has mainly been cross-sectional, prevalence-based, and from high-income countries, although rates of chronic diseases and related mortality are highest in low- and middle-income countries. There is also a lack of research comparing countries at varying levels of development to determine how multimorbidity progression might differ. This study uses longitudinal data from Costa Rica, Mexico, and the United States and an incidence-based multistate Markov approach to estimate multimorbid life expectancy (MMLE): the years someone is expected to live with multimorbidity. We disaggregate MMLE into disability-free and disabling states to understand severity progression and stratify models by gender and education to study within-country heterogeneity. Individuals from Costa Rica have the lowest MMLE, followed by those from Mexico, then the United States. Individuals from the United States spend about twice as long with disability-free MMLE compared to others. Women generally have higher MMLE than men across countries. In the United States, disability-free MMLE increases and disabling MMLE decreases with education. This study found widespread MMLE inequalities in gender, education, and disability status. More attention must be paid to the drivers of these disparities, such as life course and health system differences across contexts.