Education and cognitive function among older adults in Brazil and Mexico.

Education is protective against cognitive impairment. We used nationally representative data from Mexico and Brazil to assess the association between education and cognitive function. The sample included adults ≥ 50 years from the Brazilian Longitudinal Study of Aging (ELSI) and the Mexican Health and Aging Study (MHAS). Participants were classified as cognitively impaired or not impaired. We used logistic regression models to estimate the association between education and cognitive function. Education level was higher in MHAS than in ELSI. Participants with at least 1 year of education were less likely to have cognitive impairment than those with no formal education in both cohorts. Men in ELSI had higher odds for cognitive impairment compared to men in MHAS. In both cohorts, higher educational level was associated with lower odds of cognitive impairment compared to no formal education. Sex was an effect modifier in MHAS but not in ELSI. HIGHLIGHTS: Cognitive test batteries were harmonized using a regression-based approach.Even very low levels of education were associated with reduced odds of cognitive impairment compared to no formal education.Brazilians were more likely to have cognitive impairment than Mexicans given the same education level.The differences in the association of education with cognition between Brazil and Mexico were only observed among men.

Attrition in panel surveys in Mexico: The Mexican Health and Aging Study (MHAS).

Este trabajo analiza la atrición de la Encuesta Nacional sobre Salud y Envejecimiento en México entre el 2001 y el 2012, un proyecto longitudinal sobre adultos mayores. Para la tercera ronda de este operativo estadístico, la pérdida acumulada representó la tercera parte de la muestra inicial; la principal causa fue por fallecimiento, seguida por la no localización y el rechazo. Con modelos de regresión se examinan asociaciones de características económicas, de salud y sociodemográficas de los participantes en el 2001 con cada tipo de atrición en el 2003 y el 2012. Los resultados señalan que las variables de salud tuvieron mayor asociación con la pérdida por fallecimiento, mientras que las características económicas y sociodemográficas estuvieron asociadas con la no localización y el rechazo. Documentar el carácter de la atrición proporciona valiosos elementos para investigaciones basadas en la ENASEM, pues los resultados longitudinales podrían ser afectados por un posible sesgo selectivo en la muestra. The Mexican Health and Aging Study (MHAS) is a longitudinal project focused on older population. In this paper, we analyze attrition in three rounds of the study, between 2001 and 2012. The attrition represents a third of the initial sample in wave three. Death is the main cause of attrition, followed by lo to follow-up and refusal. Using regression models we examined associations of health, economic and demographic characteristics of participants and survey characteristics in 2001 on each cause of attrition in 2003 and 2012. Results indicate that health variables such as the number of chronic diseases have a greater association with death attrition, while economic and demographic characteristics of the study participants are associated with loss to follow-up and refusal. Documenting the character of attrition provides valuable information for research based on the MHAS data, since the results of longitudinal studies could be affected by a possible selectivity bias in the sample.