Autism spectrum disorder co-occurring conditions and change of autism spectrum disorder diagnosis

Due to the high rates of co-occurring disorders coupled with varying rates of diagnosis stability in children with an autism spectrum disorder (ASD), there is a need for better understanding of the role co-occurring disorders play in determining ASD diagnosis and diagnosis stability. This study investigated associations between common co-occurring conditions in ASDs (ADHD, learning disability, developmental delay, speech problems, hearing problems, anxiety, depression, behavioral or conduct problems, and seizures or epilepsy) and ASD diagnosis change. Based on parent-reported data from US 2007 National Survey of Children's Health dataset, two study groups across three developmental stages were defined: 1) current ASD diagnosis (n=154 for ages 3-5; n=373 for ages 6-11; n=386 for ages 12-17), and 2) past but no current ASD diagnosis (n=53 for ages 3-5; n=189 for ages 6-11; n=211 for ages 12-17). Multinomial logistic regression was used to investigate the associations between the co-occurring conditions and ASD diagnosis stability. Results indicated that co-occurring conditions distinguishing the two study groups are: 1) current learning disability (Adjusted Odds Ratio [AOR]=11.07, 95% Confidence Interval [95%CI]: 2.48-49.49), current developmental delay (AOR=9.20, 95%CI: 1.90-44.42), and past anxiety (AOR=13.46, 95%CI: 1.08-167.20) in ages 3-5; 2) past speech problem (AOR=3.85, 95%CI: 1.09-13.67), current anxiety (AOR=3.51, 95%CI: 1.28-9.65), and past hearing problem (AOR=0.23, 95%CI: 0.06-0.83) in ages 6-12; and 3) current speech problem (AOR=3.91; 95%CI: 1.56-9.75), current mild seizure/epilepsy (AOR=10.48; 95%CI:2.25-48.87), and past hearing problem (AOR=0.11; 95%CI: 0.01-0.93) in ages 13-17. Questions remain as to whether ASD diagnosis is due to etiologic differences or diagnostic determination.