Variation in the Use of Guideline-Based Care by Prenatal Site: Decomposing the Disparity in Preterm Birth for Non-Hispanic Black Women

Introduction: Despite longstanding status as a public health priority, preterm birth rates continue to be higher among non-Hispanic Black women compared with other racial and ethnic groups. A growing body of literature highlights the site of care as a key factor in pregnancy outcomes. Although research shows that many individuals do not receive guideline-based prenatal care, little is known about site-level variation in the use of recommended prenatal services and its potential relationship with Black-White preterm birth disparities. Methods: In this cross-sectional cohort study, we analyzed variation in site-level use of 4 key prenatal services: tetanus, diphtheria, and pertussis (Tdap) vaccination, [per the CDC website] and screening for bacteriuria, diabetes, and group Beta streptococcus, using administrative data from New York State Medicaid and the American Community Survey. We used multivariable logistic regressions to estimate the odds of attending a low-use site (mean <2 services per patient) by race and ethnicity, controlling for age, high-poverty residential address, and low prenatal care attendance. We performed Fairlie decomposition analyses to quantify the contribution of individual and site-level factors to the observed difference in preterm birth rates among Black and White non-Hispanic women. Results: Site-level use of recommended prenatal services ranged from an average of 1 to 3.6 services per patient. Non-Hispanic Black women had more than twice the odds (adjusted odds ratio, 2.42; 95% CI, 2.32-2.52) of attending a low-use site compared with non-Hispanic White women. Among factors in the decomposition analysis, site-level screening for bacteriuria and diabetes accounted for the highest proportion of the explained variance in the observed preterm birth rates for non-Hispanic Black (10.7%) and non-Hispanic White (6.7%) women. Discussion: Results from this research support immediate improvement in guideline-based prenatal care to narrow the gap in preterm birth for non-Hispanic Black women. Research is needed to identify and correct site-level barriers to recommended prenatal services.