Evaluation of a Multilevel Intervention to Reduce Preterm Birth Among Black Women in Newark, New Jersey: A Controlled Interrupted Time Series Analysis

Objective To evaluate the effectiveness of a multilevel intervention, Healthy Babies are Worth the Wait (HBWW), in reducing preterm birth (PTB) and very preterm birth (VPTB) among black women in Newark, NJ. Methods HBWW is a program linking the local March of Dimes office, providers, community-based organizations, and public health institutions to increase uptake of evidence based preterm birth interventions. We used birth certificate data before (2009–2011) and after (2012–2015) the introduction of HBWW in Newark. We estimated differences in PTB and VPTB between these periods among black women in Newark and compared them to rate differences among black women in the rest of NJ (difference-in-differences). We used interrupted time series analysis (ITSA) to examine declines in PTB and VPTB following the introduction of HBWW controlling for secular trends. All models adjusted for maternal age, education and parity. Results PTB declined in Newark 1.1 case per 100 (95% confidence interval (CI) − 2.3, 0) and in the rest of NJ 0.5 case per 100 (− 1.4, 0.4) (difference-in-differences = 0.6 fewer cases per 100 in Newark, 95% CI − 1.6, 0.3). VPTB declined in both Newark (− 0.6 cases per 100, 95% CI − 1.0, 0) and the rest of NJ (− 0.2 cases per 100, 95% CI − 0, 0.3) (difference-in-differences = 0.4 fewer cases per 100 in Newark, 95% CI − 0.9, 0). However, using ITSA the downward VPTB trend in Newark was not different from the rest of NJ or pre-intervention trends. Conclusions for Practice Our study supports the importance of critically evaluating and advancing complex interventions to reduce PTB among black women.