Do preterm birth disparities exist in Hawaii

Recent estimates of the distribution and trends of preterm birth phenotypes in the State of Hawai'i are currently unavailable. Much preterm birth research has focused on individual explanations of preterm birth and racial/ethnic disparities in the USA. Recently more studies are exploring social contributions to preterm birth risk and racial/ethnic disparities. Using Hawai'i's birth certificate data this study explores whether maternal racial/ethnic affiliation and health service area preterm birth disparities exist. This study may contribute to preterm birth disparities research in the nation, specifically those affecting Hawaiians, Pacific Islanders and Asians in Hawai'i. Analyses: The distributions of preterm birth phenotypes (gestational ages and delivery types) by maternal racial/ethnic affiliation and geographic residence, in Hawai'i from 2003 to 2008, are provided. Associations between maternal racial/ethnic affiliation and area poverty level with preterm birth phenotypes are explored using multilevel regression modeling. Results: Filipinos had the highest singleton preterm birth rates followed by Blacks, Other Pacific Islanders, Hawaiians/Part Hawaiians, and the Japanese. Caucasians had the lowest singleton preterm birth rates. Preterm birth disparities for the youngest gestational ages exist for Hawaiians/Part Hawaiians and Blacks that were not explained by individual covariates or the area poverty predictor. Many of Hawai'i's Asian racial/ethnic groups had statistically significant lower odds ratios for preterm deliveries resulting from prelabor preterm rupture of membranes and medical indications than other racial/ethnic groups. These lower odds ratios remained when individual covariates and the poverty predictor were added to the regression models. Maternal residential area poverty level contributed minimally to preterm birth phenotype risk or disparities in Hawai'i. However, statistically significant differences in preterm birth phenotypes were demonstrated across the State's geographic areas that remain unexplained. Conclusion: Racial/ethnic preterm birth disparities exist in Hawai'i. Significant differences in preterm phenotype risk were demonstrated across geographic regions that were not explained by area poverty level. More studies are needed to investigate social correlates with preterm birth phenotypes. Studies are also needed that explore the interactions between individual and social level correlates.