Autism spectrum disorder (ASD) is a developmental disability characterized by repetitive behaviors and persistent impairments in social interaction and communication. The prevalence of ASD has been increasing since 2000, with inconsistent findings in racial/ethnic disparities.^1-3 Over the past decade, the racial/ethnic disparities have persisted but have narrowed in response to the US Health and Human Services Action Plan to Reduce Racial and Ethnic Health Disparities.⁴ However, it remains unknown how racial/ethnic disparities have changed over time. We used recently released data from the National Health Interview Survey to assess the most recent temporal trends and racial/ethnic disparities in ASD prevalence from 2014 through 2019.

This repeated cross-sectional study used nationally representative data for 2014 through 2019. The National Health Interview Survey uses a stratified multistage sample design and collects data on a wide range of health-related topics through in-person household interviews. The University of Tennessee Health Science Center institutional review board reviewed the study protocol and granted an exemption from full review. Informed patient consent was also waived because the study was a secondary analysis of deidentified data. We followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline for cross-sectional studies.

Race/ethnicity for this study was self-reported. Following the design and estimation guidelines for the National Health Interview Survey survey,⁵ we used a survey procedure in SAS version 9.4 (SAS Institute Inc) to account for the complex sampling design, and analyzed the data for race-specific prevalence and by sociodemographic and clinical characteristics. To identify time trends across survey years, we performed weighted linear regression analyses, in which the survey year was treated as a continuous variable, with adjustment for potential confounders. The SEs were estimated using Taylor series linearization, and 2-sided P < .05 indicated statistical significance.