Expansion of disability across successive Mexican birth cohorts: a longitudinal modelling analysis of birth cohorts born 10 years apart.

BACKGROUND

Life expectancy (LE) in Mexico has risen rapidly since the 1950s. In high-income contexts, these increases have coincided with a compression of disability to later ages. However, little evidence on trends in disability-free LE (DFLE) exist from Mexico or elsewhere in Latin America.

METHODS

Using data from the Mexican Health and Aging Study, we compare changes in LE and DFLE in ages 50-59, 60-69 and 70-79 using birth-cohort-specific multistate lifetable models across successive 10-year birth cohorts. Disability was measured using the Katz activities of daily living (ADL) index, and limitation was measured using a seven-item questionnaire on physical functioning.

RESULTS

Overall, Mexican adults born in 1953-1962 lived 0.87 (p<0.001) fewer active years between ages 50 and 59 than individuals born in 1942-1951, a difference comprised of a 0.54-year (p<0.001) increase in physically limited LE and a 0.27-year (p<0.001) increase in ADL-disabled LE. Active LE declined by 1.13 (p<0.001) years in ages 60-69, and by 0.93 (p<0.001) years in ages 70-79, across successive 10-year birth cohorts. No substantial changes in total LE were seen in any age group, and the magnitude of the expansion of disability was larger in females than in males.

CONCLUSIONS

Our results indicate that more recently born cohorts of Mexican adults are spending more years of life with physical limitations and disabilities. These results foreshadow a need to closely monitor adult health in middle-income contexts, as the epidemiological conditions under which disability has expanded in Mexico are similar to those seen in many other countries.