Association of smoke‐free laws with preterm or low birth weight deliveries—A multistate analysis

Objective

To assess the association between the change in statewide smoke‐free laws and the rate of preterm or low birth weight delivery hospitalizations.

Data Source

2002‐2013 Healthcare Cost and Utilization Project State Inpatient Databases.

Study Design

Quasi‐experimental difference‐in‐differences design. We used multivariate logistic models to estimate the association between the change in state smoke‐free laws and preterm or low birth weight delivery hospitalizations. The analyses were also stratified by maternal race/ethnicity to examine the differential effects by racial/ethnic groups.

Data Collection/Extraction Methods

Delivery hospitalizations among women aged 15‐49 years were extracted using the International Classification of Diseases, Ninth Revision, and Diagnosis‐Related Group codes.

Principal Findings

Non‐Hispanic black mothers had a higher rate of preterm or low birth weight delivery hospitalization than other racial/ethnic groups. Overall, there was no association between the change in smoke‐free laws and preterm or low birth weight delivery rate. Among non‐Hispanic black mothers, the change in statewide smoke‐free laws was associated with a 0.9‐1.9 percentage point ( < .05) reduction in preterm or low birth weight delivery rate beginning in the third year after the laws took effect. There was no association among non‐Hispanic white mothers. A decline in the black‐white disparity of 0.6‐1.6 percentage points ( < .05) in preterm or low birth weight delivery rates was associated with the change in state smoke‐free laws.

Conclusion

The change in state smoke‐free laws was associated with a reduction in racial/ethnic disparities in preterm or low birth weight delivery hospitalizations in selected US states.