Alejandra Michaels-Obregon

Cohort Profile: The Mexican Health and Aging Study (MHAS)

The Mexican Health and Aging Study (MHAS) was designed to prospectively evaluate the impact of disease on the health, function and mortality of adults over the age of 50 in both urban and rural areas of Mexico. The overall goal of the study is to examine the ageing process and its disease and disability burden in a large representative panel of older Mexicans, using a wide socioeconomic perspective. The study protocols and survey instruments are highly comparable to the U.S. Health and Retirement Study (HRS).The MHAS 2001 baseline is a nationally and urban-rural representative survey of individuals born in 1951 or earlier. Three waves of data have been collected so far: baseline in 2001 and follow-ups in 2003 and 2012. In 2012, the study added a representative sample of the population from the 1952-62 birth cohorts. A fourth wave will be collected in 2015.The data files and documentation are available free of charge at the study website [www.MHASweb.org] in English and [www.ENASEM.org] in Spanish.

The Impact of Physical Activity on Disability Incidence among Older Adults in Mexico and the United States.

Evidence suggests that transitions among older adults towards healthy habits, such as physical activity, appear underway in developed countries such as the USA but not in developing countries such as Mexico. However, little is known about the potential benefit of physical activity in preventing disability among elders in countries at different stages of epidemiological transition. We explore the impact of physical activity on the disablement process among elders in Mexico compared to the USA. Data are from two waves of the Mexican Health and Aging Study and the Health and Retirement Study. We examine the impact of exercise on the transition from no disability to ADL limitations two years later. Findings indicate that exercise is more common in the U.S. than in Mexico. There is a positive effect of exercise on negative outcomes in both countries. However, the protective effect of exercise is stronger in the U.S. than in Mexico.

Older adults under a mixed regime of infectious and chronic diseases

OBJECTIVE Analyze the impact of a mixed regime of infectious and chronic conditions among older adults in Mexico on their health progression. MATERIALS AND METHODS A total of 12 207 adults from the Mexican Health and Aging Study were included. Logistic regression analyses were conducted to assess the relationship between self-reported health (SRH) and covariates, including infectious and chronic diseases. Changes in SRH between 2001-2003 were analyzed using multinomial analysis. RESULTS Older age, low SES, poor SRH and type of disease at baseline increase the odds of poor SRH at follow-up. Odds of poor SRH are highest for persons with both types of diseases (OR 2.63, SE 0.24), followed by only chronic (OR 1.86; SE 0.12) and finally only infectious (OR 1.55; SE 0.25). CONCLUSION Mexico is experiencing a mixed regime of diseases that affects the health and well-being of older adults. Despite the rising importance of chronic diseases in countries like Mexico, it is premature to disregard the relevance of infectious diseases for public health.

Cross-National Differences in Disability Among Elders: Transitions in Disability in Mexico and the United States

OBJECTIVES Little is known about how exposure to a combination of infectious and chronic conditions throughout the lifecourse could impact disability in old age. This paper compares 2 cohorts of adults who have aged under very different country contexts by contrasting disability transitions among elders in Mexico with elders in the United States. METHODS Data comes from the Mexican Health and Aging Study (MHAS) and the U.S. Health and Retirement Study (HRS). Estimated probabilities of 2-year transitions among disability states and mortality are presented for adults aged 50 and older. RESULTS The levels of disability prevalence and 2 year transitions are consistent with a higher rate of disability for the United States compared to Mexico. In 2-year transitions, the U.S. sample was more likely to transition to a disabled state or increase the number of disabilities than the Mexican counterparts, while Mexicans are more likely to move out of disability or reduce the number of disabilities reported. DISCUSSION The findings suggest that the current rate of disability in old age is lower for a less developed country compared with a developed society. We discuss implications, possible explanations, and likely future scenarios.

BMI and Transitions to Disability Among Older Adults in Mexico and the United States

As national populations across the world age at an unprecedented rate, disability rates are also increasing (World Health Organization, & The World Bank. (2011). World report on disability, from http://whqlibdoc.who.int/publications/2011/9789240685215_eng.pdf). Prevalence of disability varies greatly by country, however, ranging from 43.4% among persons 60 and older in lower income countries to 29.5% in higher income countries (World Health Organization, & The World Bank. (2011). World report on disability, from http://whqlibdoc.who.int/publications/2011/9789240685215_eng.pdf). High rates of disability can impact individuals’ quality of life and contribute to the health burden of society. This is particularly the case in developing countries, where access to rehabilitation services and treatment programs may be limited (Al Snih, S., Graham, J. E., Kuo, Y., Goodwin, J. S., Markides, K. S., & Ottenbacher, K. J. (2010). Obesity and disability: Relation among older adults living in Latin America and the Caribbean. American Journal of Epidemiology 171(12):1282–1288).