Ascertaining variation in hospitalization risk among immigrants using small area analysis.

INTRODUCTION: Data on hospitalization of immigrants to the United States are sparse, but small area analysis may improve the utility of existing data. METHODS: Applying logistic regression analysis to 2000 census and hospitalization data for New York City, we examined the odds of hospital admission by major diagnostic category and global region of birth after controlling for covariates. We used individual-level covariates to control for age, race, and gender. By matching the patient's zip code of residence to census data, we then added median household income, the proportion of persons born in a particular global region, and the proportion of foreign-born persons living in the same zip code as independent variables. RESULTS: The total proportion of foreign-born persons in a zip code predicts a lower hospitalization rate for most major diagnostic categories and most foreign-born groups. However, Africa-born persons have a higher odds of hospitalization for most major diagnostic categories - up to 1.79 (95% confidence interval 1.73, 1.86) for blood and blood forming disorders - relative to native-born persons. The odds of hospitalization among Africa-born persons for most conditions are over 3 times higher than other foreign-born groups. Hospitalization odds for Latin American-born persons were also higher than native-born persons across major diagnostic categories. CONCLUSION: Small area analysis generally predicts hospitalization rates that coincide with mortality studies and may serve as a useful tool for hypothesis testing in immigrant health.

Health status and hospital utilization of recent immigrants to New York City.

BACKGROUND: This paper examines hospital utilization, estimated hospital costs, and mortality rates for U.S.-born, foreign-born, and Puerto Rican-born persons residing in New York City. METHODS: We conducted a multivariate regression analysis using New York City neighborhoods as the unit of analysis. We utilized data from the Statewide Planning and Research Cooperative System data set and from the 1997 Housing and Vacancy Survey. We also examined mortality rates using 1990 death certificate data and decennial census data. RESULTS: The foreign-born are much less likely to be hospitalized for most major categories of illness and have lower mortality rates than either U.S.-born or Puerto Rican-born New Yorkers. The life expectancy at 1 year of age of the foreign-born is 4 years longer than for U.S.-born persons and 6 years longer than Puerto Rican-born persons. We estimate that the overall cost of providing hospital-based care to the foreign-born was $611 million US dollars less than the cost of providing hospital-based care to an equivalent number of U.S.-born persons in 1996. CONCLUSION: The foreign-born in New York City appear to be healthier and consume fewer hospital resources than U.S.-born populations. It is possible that the cost of hospital utilization would be lower still if the foreign-born population had better access to ambulatory and preventive services.