Standardized screening facilitates timely diagnosis of autism spectrum disorders in a diverse sample of low-risk toddlers.

Objective: Routine, standardized screening for autism spectrum disorder (ASD) has been hypothesized to reduce known racial/ethnic and socioeconomic status (SES) disparities in age of first diagnosis. This study explored demographic differences in toddlers' age and performance on developmental measures at the time of ASD assessment.

Method: Toddlers (16-39 months at evaluation) who screened at-risk for developmental delay on the Modified Checklist for Autism in Toddlers (M-CHAT) or M-CHAT-Revised (M-CHAT-R) and follow-up interview participated in a diagnostic assessment. Of these, 44.7% were racial/ethnic minorities and 53.5% were non-minorities. Child race/ethnicity, years of maternal education (MEd), and household yearly income (YI) were parent-reported.

Results: Small but significant correlations were observed between MEd or YI and evaluation age and adaptive communication, socialization, and motor scores. Controlling for MEd and YI, minority racial/ethnic group did not predict child's performance on most measures and did not predict likelihood of ASD diagnosis. Differences in age at evaluation and receptive language skills were small effects.

Conclusion: Significant but small effects emerged for SES and minority status on toddlers' age at evaluation and parent-reported adaptive skills, but these did not predict ASD diagnosis. The small magnitude of these effects suggests that routine, standardized screening for ASD in toddlers and timely access to diagnostic evaluation can reduce disparities in age at diagnosis and possibly reduce racial/ethnic disparities in access to services for ASD and other developmental delays.