Demographics and Diagnosis: Early Findings from the Autism Center of Excellence and Simons Simplex Collection Studies at UIC

Background: Early recognition and diagnosis of autism spectrum disorders (ASDs) is imperative given the benefits of early intervention. For a particular demographic of children however, there may obstacles to obtaining a warranted diagnosis of an ASD. Though population research has found no differences with regard to the prevalence of ASDs among different ethnicities (Bertrand et al., 2001), work by Mandell and colleagues (2002) found that White children receive a diagnosis of autism an average of 1.4 years earlier than African-American children. What is more, compared to their White counterparts, African-American children are significantly more likely to first receive another diagnosis, such as Attention Deficit/Hyperactivity Disorder (Mandell et al., 2007).

Differences with regard to diagnosis may be even greater as previous studies have restricted their analyses to include only children diagnosed with Autistic Disorder. As such, it is not clear whether population differences exist in the detection and diagnosis of individuals with milder presentations of ASDs. In addition, examining these differences with the use of standardized diagnostic instruments is needed to further our understanding of disparities in diagnosis.

Objectives: This study will examine differences in age of first diagnosis among population groups as well as identify differences in diagnoses assigned prior to the diagnosis of an ASD. 

Methods: Subjects will include approximately 120 individuals, ages 3-28 years, participating in genetic studies of autism. Ninety of these subjects identified as White and 30 subjects identified as ethnic minorities. Because of the small number of individuals in ethnic minority categories, these subjects will be collapsed into one category. ASD diagnosis will be confirmed by the use of the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule (ADOS), and DSM-IV criteria. Analyses will be completed to compare population groups on demographic characteristics and age of first diagnosis. In addition, analyses will examine differences in the diagnoses assigned prior to the ASD diagnosis.

Results: Results of the data analysis described above will be presented. Implications for early identification, diagnostic instrument choice, and clinical education will be discussed. Conclusions: These results will add to our existing knowledge of disparities in the diagnosis of ASDs. Important contributions include the use of gold standard diagnostic instruments and the inclusion of individuals diagnosed with high-functioning ASDs.