Changes from 2001 to 2012 in the Characteristics of Youth on the Autism Spectrum Receiving Special Education Services in the U.S.

Background: The autism spectrum encompasses a range of abilities and challenges. In childhood, lower rates of intellectual disability and impairment severity have been documented in more-recent cohorts. However, we know very little about corresponding changes in the distributions of characteristics and needs among the population of transition - age youth and young adults which hinders development of effective services, policies and practices for this vulnerable population .

Objectives: Describe how the characteristics of the identified population of high school students in the autism special education category changed from 2001 to 2012. Dependent variables included impairment and health characteristics, youth demographics, household and family characteristics.

Methods: We used secondary data from two related cohort studies that were funded by the U.S. Department of Education and conducted 10 years apart: Wave 1 (2001-2002) of the National Longitudinal Transition Study-2 and the National Longitudinal Transition Study-2012. Both studies were designed to yield nationally representative estimates of the characteristics and experiences of youth with special needs who received special education services. We limited analyses to youth who were ages 13 to 17 years. We used logistic regression to estimate differences in cohorts for each variable, while controlling for weights and sample characteristics. Rates of missing data per variable ranged from 0% to 12% across both surveys. We imputed missing data using multivariate imputation by chained equations (MICE) methods to create 50 implicates.

Results: The 2012 cohort was less racially diverse than the 2001 cohort (78% White v. 65%) and included more households receiving food stamps (19% in 2012 vs. 8% in 2001). Reported age when disability or concern was first noted was older, on average, among the more-recent cohort (3.0 years vs. 2.3 years). On average, members of the recent cohort had less severe communication impairments. For instance, in response to a question about how well youth could carry on a conversation, parents of 35% of recent cohort members said “Not at all” or “With a lot of trouble” vs. 55% of the 2001 cohort members. The recent cohort had higher scores on most functional skills measures. For instance, 58% were able to get to places outside the home “Very well” or “Pretty well” compared to 47% for the earlier cohort. Sex ratio, overall health, and the rate of psychotropic medication use were comparable across cohorts.

Conclusions: The average severity of parent-reported functional and communication impairments among youth identified with autism decreased from 2001 to 2012. Members of the recent cohort of teens served in the autism special education category are, on average, diagnosed later, are less impaired and have higher functional skills across a variety of survey questions asked of parents. The design of services and policies need to become more nuanced and specific to particular subpopulations because there can be no one-size-fits-all solutions for such a diverse and changing population.