In recent years, the Autism and Developmental Disabilities Monitoring Network has observed a shift in racial disparities in autism. To delineate the historical shift of racial disproportionality in US autism prevalence, our literature review examines three key topics: publication trends concerning racial disproportionality in autism, discernible national and state-level patterns, and underlying factors contributing to the disproportionality. Using the PRISMA framework, we synthesized 24 empirical studies on racial disproportionality in autism and its change over time. These studies explored national patterns and spatiotemporal variations to provide a comprehensive understanding of racial disparities in autism. Studies indicated similar national patterns for Black and Asian racial groups; both groups had had mixed results around the turn of the millennium. By 2007, the Asian group was overrepresented again. Hispanic and Native American groups have consistently been underrepresented. However, significant spatiotemporal variations were found, suggesting that these disparities might reflect inherent inequalities within the current identification and classification system. The patterns of racial disproportionality in autism seem to be influenced by numerous factors. These include varying state definitions of autism, disparities in resource distribution, differences in symptom recognition across cultures, service preferences, cultural mismatches between professionals and families, and prevailing biases and stigmas, as revealed by the reviewed studies. These findings prompt a closer look into the causes and implications of these disparities, offering the underlying issues within the current diagnostic system and highlighting the need for further research to ensure equal educational opportunities regardless of disabilities and race/ethnicity.
