Racial and Ethnic Differences in Rates of Prolonged Autism Diagnosis Process & Prior Diagnoses in Mental Health...

A prolonged diagnostic process (PDP), in which an autism diagnosis is received > 90 days after entering specialty mental health (SMH) care, can hinder early and equitable diagnosis. Given recent changes in autism prevalence, we hypothesized PDP would be less common and racial and ethnic disparities less pronounced than previously reported.

Claims data were analyzed from 21,586 Medicaid-enrolled children ages 2-8 years entering SMH care in 2017, who received an autism diagnosis in the subsequent two years. Race and ethnicity, as captured by enrollment data, were the primary exposures; PDP was the primary outcome. Further analysis assessed diagnoses received before autism by exposure.

Overall, 21.2% of children had an autism PDP with substantial interstate variability (14-31%). In adjusted models, American Indian and Alaska Native (AIAN), Asian, and Hispanic children had a lower probability of PDP than white children. Among children with PDP, the most common prior diagnoses were ADHD or speech and language disorders. In adjusted models, ADHD diagnosis before autism diagnosis was less likely for Hispanic and Asian children but more likely for AIAN children than white children. Speech and language disorder diagnoses before an autism diagnosis were more likely among Asian, Black, Hawaiian/Pacific Islander, and Hispanic children.

Current racial and ethnic disparities in PDP were narrower than those previously reported; however, disparities persist in diagnoses before autism. Findings highlight the need for SMH providers to receive more education on differential diagnoses for autism and coexisting mental health conditions. PDP variation across states further supports focusing on state-level care differences.