Educational Outcomes from a Longitudinal Study of the SSC Cohort

Background: The Simons Simplex Collection (SSC) contains 2,644 families, each with only one family member with an Autism Spectrum Disorder (ASD). Approximately 1,500 participants joined the online research registry SSC@IAN (Interactive Autism Network) and were invited to complete an online longitudinal follow-up study questionnaire. This study examines predictors of educational outcomes in dependent and independent adults with ASD.

Objectives: To describe educational outcomes in adults with ASD in SSC.

Methods: Full scale IQ (FSIQ), Autism Diagnostic Observation Schedule (ADOS) and Vineland Adaptive Behavior Scales-2^ndeditionwere collected at baseline in 8 to 17-year olds in the SSC, and education history and other updates were completed at follow-up an average of 8 years later. Regression analysis was conducted for predictors of current and completed level of education, specifically college attendance.

Results: Of 84 dependent and 23 independent adults completing the follow-up survey, 80% were male, and the majority of the sample was of European ancestry (88%). The mean age at follow-up was 21 years (range 18 to 26). 78% of adults declared independent had average-or-above IQ in childhood vs. 20% of those declared dependent. Together, at baseline, FSIQ distribution showed: 41% <70 (impaired), 14% 70-79 (borderline-impaired), 12% 80-89 (low average), 17.7% 90-109 (average), 5.6% between 110-119 (high average), 9.3% >120 (superior and very superior range). 67.2% had fluent speech (Module 3/4), but mean Vineland expressive language age equivalent (AE) was 5.2 years. Mean ADOS Calibrated Severity score (CSS) was 7.6.

Level of completed education at follow-up was categorized as: alternate special education diploma (39.6%), high school diploma or GED (37.5%), some college coursework (6.2%), bachelor’s degree (10.4%), and other/ “not sure” (6.3%). In terms of those currently attending school (55%), 49% are attending high school, 11%, vocational/trade school, and 40%, college.

Of those who completed a bachelor’s degree or some college, including those currently attending college, 70% had average-to-above average IQ at baseline, while 30% had below average to impaired IQ. 97% had fluent speech by school age (ADOS Module 3). Mean expressive language AE was 7 years (range 2-10.5) at baseline. 73.3% had a moderate to severe CSS (6-10).

In multiple regression analysis, FSIQ score significantly predicted college attendance (p<.0005), while severity (CSS) and language level (ADOS module or Vineland expressive AE) were not significant.

Conclusions: Outcome in adulthood is a common concern of parents of children with ASD. The SSC@IAN cohort provides the opportunity to investigate longitudinal outcomes. Of the now-adult SSC participants who completed the follow-up study, over 25% later attended college, including those who are not legally independent in adulthood. Individuals who go on to attend college show a surprisingly wide range of IQ and symptom severity; however, similar to other outcome research in ASD, IQ is the best predictor of later attainment. Identification of reliable predictors can helpfamilies to prepare for the future.