Disparities in the effect of state policy for the newborn screening for critical congenital heart diseases - Inequities in health outcomes for infants from lower social economic groups; uninsured, publicly insured, or rural families, and marginalized racial and ethnic groups result in disturbing mortality statistics, especially among Black infants. Therefore our proposed study looks at Critical Congenital Heart Disease (CCHD), the most severe forms of congenital heart disease, requiring surgery or catheter-based interventions within the first year. Occurring in 7,200 newborns and causing about 1,260 infant deaths in the U.S each year, mortality for congenital heart disease is between 35-40% higher among Black infants in their first year than their White counterparts, depending on subtype and state healthcare model. Currently, advances in ultrasound and echocardiography, diagnostic tools that are expensive and require advanced skills, allow certain types of CCHD to be diagnosed prenatally among women. Yet, inequities are substantial in prenatal detection rates, which are 71-100% in teaching hospitals, and 0-39% in non-teaching hospitals. All 50 states and D.C. now mandate newborn screening using Pulse Oximetry (POx), a screening added to the Recommended Uniform Screening Panel in 2011 which can cost-effectively screen for CCHD with a simple and non-invasive procedure. Full access and correct use of POx provides the last best opportunity for prompt diagnosis to prevent mortality and secondary morbidities in under-resourced and marginalized communities. For our proposed study, we hypothesize that health outcomes will improve and healthcare utilization decrease more for historically underserved and marginalized populations than their more privileged counterparts after implementation of state POx screening mandates, and especially among Black infants, given the high mortality inequities. We will examine hospital, birth, and death records from ten states (FL, GA, MA, MI, MO, NE, PA, SC, TN, WA) and one city (NYC), covering over one third of U.S. live births, to assess differences in the effect of state-mandated POx screening policies on traditionally underserved and marginalized populations and their more privileged counterparts. Outcomes will include [1] infant deaths due to CCHD, [2] infant deaths due to missed or late diagnoses of CCHD, and [3] use of healthcare resources during infancy among CCHD patients, such as hospitalization cost and length of stay. A difference-in-differences model, which is commonly used to evaluate the changes in outcomes associated with health care policy implementations, will be used. If mandatory screening narrows gap to improved outcomes among under- resourced and marginalized populations, and especially Black infants, the next step will be a mixed methods R01 to link mother and child health data, including registries, to determine characteristics that increase likelihood of developing CCHDs. Using in-depth interviews and a questionnaire survey, we will develop interventions targeted to marginalized families to promote prenatal care and prenatal CHD detection, and the expansion of POx screening.