Demographic Predictors of Diagnostic Timing in Autism Spectrum Disorder and Co-occurring Mental Health Conditions: Evidence From Pediatric Electronic Health Records

OBJECTIVE: The present study examined the diagnostic sequencing of co-occurring autism spectrum disorder (ASD) and mental health diagnoses in youth and the impact of demographic factors on diagnostic patterns. METHODS: Data were extracted from the electronic health record of youth (n = 3357) under age 18 years in a pediatric health care system in the midwestern United States. Patients with co-occurring ASD and mental health disorders were categorized based on the order in which they were diagnosed: ASD first, mental health disorder first, or concurrent diagnoses. T -tests and linear and multinomial regressions were used to examine whether age at ASD diagnosis differed based on the presence of a mental health disorder and to examine demographic variables as predictors of diagnostic patterning. RESULTS: ASD was diagnosed 3 years later in youth with a mental health disorder, t(13,464) = 34.26, p < 0.001. Youth were most often diagnosed with a mental health disorder before ASD. Girls were 0.65 times less likely than boys to receive an ASD diagnosis first compared with a mental health diagnosis first ( p = 0.006) and were diagnosed with ASD later than boys (B = 0.97, p = 0.006). Black and multiracial Hispanic children were more likely than White children to receive an ASD diagnosis first compared with a mental health diagnosis (odds ratios 1.37-1.93) and were diagnosed with ASD earlier. Minoritized children were more likely to receive externalizing diagnoses. CONCLUSION: Findings highlight issues of diagnostic overshadowing in the diagnosis of ASD and co-occurring mental health conditions, and elucidate demographic groups who may be at risk for late diagnosis of ASD.