Neighborhood-Level Immigrant Concentration and Infant Mortality in Los Angeles County

Background: Infant mortality rates are generally lower for Latinos than would be expected on the basis of socioeconomic characteristics. Individual-level factors have not explained this ‘paradox'; thus, neighborhood context may be important. Immigrant enclaves are hypothesized to be protective for infant mortality among Latinos, but this hypothesis has not been tested.

Methods: Infant and maternal characteristics were obtained from geocoded Los Angeles County 2002-2006 vital statistics records. Data on neighborhood characteristics were obtained from the 2000 Census. The primary neighborhood variable of interest, immigrant concentration, was constructed via factor analysis and included percentages of foreign-born residents, non-citizens, immigrants, Spanish-speaking adults, and Latinos (Cronbach's alpha: 0.88). Neighborhoods were defined as census tracts. Logistic models of infant mortality, stratified by race/ethnicity, were estimated using random effects models to account for spatial clustering.

Results: Infant mortality rates were similar among white and Latino infants. Latino infants whose mothers lived in neighborhoods with the lowest immigrant concentration had reduced odds of mortality. The odds ratio for mortality for Latino infants in the lowest quartile of immigrant concentration vs. those in the third quartile was 0.65 (95% CI: 0.48-0.86). Neighborhood median income was not significantly associated with infant mortality among Latinos. However, lower neighborhood income had a stronger negative effect on mortality in areas of high immigrant concentration.

Conclusions: In Los Angeles County, immigrant enclaves were not associated with a lower risk of infant mortality for Latinos. This may be due, in part, to lower neighborhood incomes in areas of high immigrant concentration. This interaction warrants further exploration.