Background: Immigrants are a growing segment of the US population. In 2003, there were 33.5 million immigrants, accounting for 12% of the total US population. Despite a rapid increase in their numbers, little information exists as to how immigrants' health and mortality profile has changed over time. In this study, we analysed trends in social and behavioural characteristics, life expectancy, and mortality patterns of immigrants and the US-born from 1979 to 2003.
Methods: We used national mortality and census data (1979-2003) and 1993 and 2003 National Health Interview Surveys to examine nativity differentials over time in health and social characteristics. Life tables, age-adjusted death rates, and logistic regression were used to examine nativity differentials.
Results: During 1979-81, immigrants had 2.3 years longer life expectancy than the US-born (76.2 vs 73.9 years). The difference increased to 3.4 years in 1999-2001 (80.0 vs 76.6 years). Nativity differentials in mortality increased over time for major cancers, cardiovascular diseases, diabetes, respiratory diseases, unintentional injuries, and suicide, with immigrants experiencing generally lower mortality than the US-born in each period. Specifically, in 1999-2001, immigrants had at least 30% lower mortality from lung and oesophageal cancer, COPD, suicide, and HIV/AIDS, but at least 50% higher mortality from stomach and liver cancer than the US-born. Nativity differentials in mortality, health, and behavioural characteristics varied substantially by ethnicity.
Conclusions: Growing ethnic heterogeneity of the immigrant population, and its migration selectivity and continuing advantages in behavioural characteristics may partly explain the overall widening health gaps between immigrants and the US-born.