Respiratory
A synthetic control analysis examining associations between smoke-free public housing policies and pediatric asthma emergency department visits in New York City Andrea R. Titus* Andrea Titus Elle Anastasiou Donna Shelley Brian Elbel Katarzyna Wyka Lorna E. Thorpe
Introduction: Secondhand smoke (SHS) remains a leading cause of morbidity in the US. To address high SHS exposure rates in multi-unit housing, the U.S. Department of Housing and Urban Development (HUD) required public housing authorities to implement smoke-free housing (SFH) policies by July 2018. We examined associations between HUD-mandated SFH policies in New York City Housing Authority (NYCHA) developments and pediatric asthma ED visits.
Methods: Children living in NYC census block groups (CBGs) comprised solely of NYCHA buildings were considered policy-exposed, while children in CBGs without NYCHA buildings were considered unexposed. We combined geocoded all-payer claims and census data to calculate quarterly, CBG-level asthma ED visit rates among children aged 0-17 from November 2015-December 2022. We used synthetic control matching to compare rates among exposed and unexposed CBGs before and after the policy, incorporating pre-policy outcome rates and CBG-level confounders, including housing age and size and sociodemographic characteristics. We estimated models for the full post-policy period, and for pre-COVID-19 and COVID-19 pandemic periods. We examined associations in the year prior to policy introduction as a negative control.
Results: We observed slightly higher asthma visit rates in policy-exposed versus unexposed CBGs (rate difference = 22.9%, 95% CI = 8.6%, 39%). Rate differences were apparent only in the pandemic period. Negative control analyses did not suggest strong residual confounding (rate difference in year prior to policy = 6.5%, 95% CI = -15.5%, 34.2%).
Conclusions: The NYCHA SFH policy was not associated with reduced pediatric asthma ED visits. Slightly elevated rates among NYCHA CBGs may represent random variation, potential behavior changes during the pandemic (e.g., displacement of smoking indoors), or differential impacts of the pandemic on health care use. Further research into the implementation and impacts of SFH policies is needed.
