Usability of NewSTEPs Data for Assessing the Characteristics of Infants with Newborn Screening Disorders

Most state newborn screening programs in the U.S. currently contribute case data to the Newborn Screening Technical Assistance and Evaluation Program (NewSTEPs). To assess the usability of these data for research, we examined the completeness of key variables, particularly race and ethnicity. Data included 24,129 cases of 34 newborn screening disorders from 45 states available in NewSTEPs as of 31 August 2020. Birth years of cases ranged between 2006 and 2020. Rates of missing data for sex, gestational age, birth weight, and race/ethnicity were 3.8%, 31.7%, 7.0%, and 39.7%, respectively. After excluding 21 states for which ≥50% of cases had missing data on race and/or ethnicity, 16,010 cases from 24 states remained. The disorders with the highest proportions in which cases were recorded as Hispanic ethnicity/any race were methylmalonic acidemia (48.7%) and maple syrup urine disease (45.7%). Analyses indicated that sex and birth weight data in NewSTEPs are reasonably complete, but missing data are common for gestational age and race/ethnicity. Despite this, our analyses revealed several novel associations between race/ethnicity and newborn screening disorders, such as the high burden of maple syrup urine disease among Hispanic patients. This demonstrates the potential usefulness of NewSTEPs for research if investments in higher-quality data are made.