Community income, smoking, and birth weight disparities in Wisconsin.

This study examined the extent to which community-level income and smoking status were associated with birth-weight disparities in the state of Wisconsin. Data included 1998 and 1999 birth record files with appended census income data for African-American, Latino, and White single births in Wisconsin. Multinomial logistic regression analysis was performed where the dependent variable included low birth weight (LBW: < 2,500 grams) and very low birth weight (VLBW: < 1,500 grams) relative to normal birth weight. The independent variables included income levels categorized as poor (< $12,499), lower middle ($12,500-34,999), and upper middle to affluent ($35,000 or more) determined by zip code, and smoking status (yes/no). African-American and Latino mothers who lived in poor communities and smoked were almost three times more likely to have a low birth weight (LBW) infant than their more affluent, non-smoking counterparts. Community income and smoking status played significant roles in birth weight disparities.