International migration is a growing global phenomenon. The magnitude of the global population living outside their countries of origin substantiates the value of considering potential public health issues and their population-wide burden. As migration has yet to be generally accepted as an exposure in and of itself, and encompasses a wide range of experiences and health effects, a measure of overall health is well suited for this research. This study compares self-rated health between two independently collected occupational cohorts as part of the ITSAL study in Spain and the MICASA study in Mendota, California, USA. We observed greater gender balance in the MICASA sample than the ITSAL sample, where there was a substantial male majority. Mexican-born workers in the MICASA sample tended to be older, less educated, and more likely to work in agriculture than their Moroccan-born counterparts in the ITSAL study. We also observed a higher prevalence of poor self-rated health in the MICASA sample compared to the ITSAL sample. Differences may be due to sampling and data collection issues, cultural issues and the subjectivity of self-rated health as an outcome, as well as actual health differences. Further research is needed to determine common and distinct migration-related public health issues.

Funding for the MICASA study was provided by the National Institute for Occupational Safety and Health (2U500H007550 and RO1OH009293) and The California Endowment. Funding for the ITSAL project was provided by the Fondo de Investigación Sanitaria, Instituto de Salud Carlos III in 2005 (PI050497, PI052202, PI052334), 2006 (PI061701), and 2007 (PI0790470).