The health of Hispanics in the United States is a complex issue that is still not well understood. Among the factors that complicate the study of Hispanic health are data artifacts and cultural differences that originate from different degrees of assimilation.
In this work, I seek to provide a better understanding of the issues surrounding the health of Hispanics in general, and of Hispanic immigrants in particular. First, in Chapter 2, I provide a brief review of the literature on Hispanic health, and I discuss the hypotheses that have been proposed to explain three important results in that literature: (1) the apparent health advantage of Hispanics over other ethnic groups, despite a relatively low socioeconomic status; (2) the decline in the health status of Hispanic immigrants as their length of residence in the United States increases; and (3) a weak or even flat association between health and socioeconomic status among Hispanics.
In Chapter 3, I examine differences in health status between non-Hispanic Whites, Mexican Americans, and Mexican immigrants. I propose an index of biological risk composed by eight biomarkers that can be split into three subcomponents: inflammatory, metabolic, and cardiovascular. The index gives more weight to biomarkers that have stronger associations with mortality, and accounts for nonlinearities in those relationships. A separate set of analyses uses the Framingham risk score, a widely used indicator of risk of coronary heart disease (CHD). In addition, I explore the application of propensity score methods for the study of health disparities as an alternative to traditional regression analyses.
To construct the health index, I use data from the Third National Health Examination and Nutrition Survey (NHANES-III, 1988-1994) with linked mortality through 2000; the propensity score analyses use data from NHANES-III and the 1999-2004 NHANES. Results with allostatic load as the outcome indicate that there is no general health advantage of Hispanics over Whites: Mexican Americans show higher (worse) scores for the general index and all three subcomponents. Mexican immigrants, on the other hand, have lower (better) inflammatory and cardiovascular scores, but higher metabolic scores, than Whites. Conversely, results using Framingham risk as the outcome suggest a general Mexican health advantage over Whites. Both US-born Mexicans and Mexican immigrants have lower 10-year risk of CHD than Whites; and Mexican immigrants enjoy an advantage in CHD risk over both Whites and US-born Mexicans. The discrepancies between the analyses that use allostatic load and those that use the Framingharn score may be explained by the inclusion of smoking as a risk factor in the Framingham score. The differences between the coefficients estimated using regression and propensity score methods are largest for the comparison of Mexican immigrants with Whites, indicating that there two groups have the largest differences in observed covariates and thus benefit the must from using propensity score methods.
In Chapter 4, I explore the Health-Age and Health-SES trajectories of Mexican immigrants using semiparametric methods. I assess the evidence supporting several of the hypotheses discussed in Chapter 2. I find indirect evidence supporting the “healthy migrant” hypothesis, which states that emigrants are positively selected in their health status from the population of their countries of origin. My results are also consistent with an apparent decline in immigrant health as the length of residence in the United States increases, a common result in the literature. However, unlike several recent studies, I find that the Health-SES gradient is similar for Whites, recent immigrants, and immigrants who have lived in the US for more than 15 years. Only immigrants who have lived between 5 and 15 years in the US appear to have a weaker gradient. Moreover, I do not find support for the “acculturation hypothesis”, which states that the decline in immigrant health with increased duration of residence is a result of assimilation into US culture. In addition, my results suggest that this health decline is not likely to be due to better average health among recent immigrant cohorts when compared to earlier immigrant cohorts. Two hypotheses to explain the decline in immigrant health remain consistent with my results: (1) the “life-course” hypothesis, which states that the deterioration of immigrant health status is a result of the cumulative negative effect of the adversities associated with the process of migration, and (2) the “regression to the mean” hypothesis, which maintains that immigrants self-select on health at the time of migration, but over time their health converges to the average health levels in their home countries. Finally, in Chapter 5, I summarize the main findings and I discuss the implications of this work for future research and public policy. (Abstract shortened by UMI.)