Autism Spectrum Disorder with and Without Co-Occurring Attention Deficit Hyperactivity Disorder: An Analysis of Pathways to Diagnosis and Intervention in a National Sample




Thomi, Morgan S.


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Autism Spectrum Disorder (ASD) is diagnosed in 1 out of 68 children. Recent changes to diagnostic guidelines permit clinicians to assign co-occurring diagnoses of ASD and Attention Deficit-Hyperactivity Disorder (ADHD). It is important for researchers and clinicians to be aware of groups vulnerable to delayed or incomplete diagnosis. In this retrospective review of data from the CDC Survey of Pathways to Diagnostics and Services (SPDS) and the National Survey of the Diagnosis and Treatment of ADHD and Tourette Syndrome (DTAT), we sought to assess the impact of race, ethnicity, sex, poverty level, and diagnosing provider type on age of first concern and age of final diagnosis in children diagnosed with ASD, ADHD, and ASD+ADHD. We predicted that age of first concern and age of final diagnosis would vary by sex, race, poverty level, identifier of first symptoms, provider type, and comorbidities. Parents/guardians of 5,959 children aged 3-17 completed the surveys; in the current sample, 2,966 cases were from DTAT and 2,993 were from SPDS. We used a series of ANOVAs to assess differences in the variables of interest by group. Age of first concern was significantly impacted (p [less than] 0.05) by Race, Race x Poverty Level, and Race x Poverty Level x Sex for the ASD+ADHD group. Age of final diagnosis was not significantly impacted (p [greater than] 0.05) by Poverty Level, Race x Poverty Level, and Sex x Race x Poverty Level for the ASD group. Identifier of first symptoms significantly impacted (p [less than] 0.05) age of first concern for all groups, while identifier of first concerns only significantly impacted (p [less than] 0.05) the ASD and ADHD groups. Post-hoc analyses revealed specific patterns of risk. Specific combinations of demographic factors increase vulnerability for later diagnosis. These findings suggest that provider- and patient-centered education is needed to increase surveillance in at-risk populations.