Cross-national health comparisons using the Rasch model: findings from the 2012 US Health and Retirement Study and the 2012 Mexican Health and Aging Study
Cross-national comparisons of patterns of population aging have emerged as comparable national micro-data have become available. This study creates a metric using Rasch analysis and determines the health of American and Mexican older adult populations.
Secondary data analysis using representative samples aged 50 and older from 2012 U.S. Health and Retirement Study (n = 20,554); 2012 Mexican Health and Aging Study (n = 14,448). We developed a function measurement scale using Rasch analysis of 22 daily tasks and physical function questions. We tested psychometrics of the scale including factor analysis, fit statistics, internal consistency, and item difficulty. We investigated differences in function using multiple linear regression controlling for demographics. Lastly, we conducted subgroup analyses for chronic conditions.
The created common metric demonstrated a unidimensional structure with good item fit, an acceptable precision (person reliability = 0.78), and an item difficulty hierarchy. The American adults appeared less functional than adults in Mexico (β = − 0.26, p < 0.0001) and across two chronic conditions (arthritis, β = − 0.36; lung problems, β = − 0.62; all p < 0.05). However, American adults with stroke were more functional than Mexican adults (β = 0.46, p = 0.047).
The Rasch model indicates that Mexican adults were more functional than Americans at the population level and across two chronic conditions (arthritis and lung problems). Future studies would need to elucidate other factors affecting the function differences between the two countries.
KeywordsCross-cultural comparison Rasch model Disability Health Outcome measure
The Health and Retirement Study (HRS) is sponsored by the National Institute on Aging (NIA U01AG009740) and the Social Security Administration. The Mexican Health and Aging Study (MHAS) is partly sponsored by the National Institutes of Health/National Institute on Aging (Grant Number NIH R01AG018016) and the Instituto Nacional de Estadística y Geografía (INEGI) in Mexico. Data files and documentation for the HRS and MHAS are public use and available at https://hrs.isr.umich.edu and http://www.MHASweb.org. We thank Dr. Sarah Toombs Smith at the University of Texas Medical Branch for copyediting the manuscript.
Compliance with ethical standards
Conflict of interest
All author declares that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This study was exempted by the Institutional review boards (IRB) of the University of Texas Medical Branch because the research is a study of an existing data sets, the US Health and Retirement Study and the Mexican Health and Aging Study which are publicly available. The study data set is de-identified, such that subjects cannot be identified directly, or through identifiers linked to the subjects.
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