Long-Term Development of Children with Autism Spectrum Disorders Following Early Intensive Behavioral Intervention: Adaptive Functioning

Background: Early intensive behavioral intervention (EIBI) is an effective intervention for many children with Autism Spectrum Disorders (ASDs). However, its long-term impact in the development of cognitive, communication, social, behavioral, and academic skills following EIBI has not been widely evaluated.

Objectives:  We conducted a 5-year longitudinal study to examine the development of children with ASDs who graduated from a community-based EIBI preschool program.  Children’s development in a number of domains was monitored during the study. For this presentation, we will focus on developmental trajectories of adaptive behavior, an area important for daily living skills.

Methods: Participants were 10 children with ASDs who graduated from a government funded community-based EIBI pre-school program. Mean age of the children was 6.26 years at the beginning of the 5-year follow-up period.

Adaptive behavior was assessed using the Scales of Independent Behavior – Revised (SIB-R), completed by parents on a yearly basis. Participant’s annual SIB-R Broad Independence Age-Equivalent score and chronological age was used to determine the rate of development during each evaluation period. Evaluation periods include: 1) prior to receiving EIBI (pre-intervention), 2) while receiving EIBI (intervention), and 3) after the completion of EIBI for up to 5 consecutive years (post-intervention). SIB-R Broad Independence standard scores were used to determine whether clinically significant gains were achieved (i.e., an increment ≥ 15 standard points).

Results: Participants’ mean rate of development during pre-intervention, intervention, and post-intervention periods were M = 0.58, 1.35, and 0.90 respectively; F(1.431, 12.878) = 6.260, p < .05 (two-tailed). None of the participants achieved typical development rates (i.e., rate ≥ 1) during the pre-EIBI period. 7 out of 10 participants achieved typical rates of development in the EIBI period, and 3 of them maintained typical rates with smaller magnitude during the post-EIBI period. Overall, mean EIBI and post-EIBI rates of development were highly correlated (r = .81).

Participants’ mean Broad Independence standard scores during pre-intervention, intervention, and post-intervention periods were M = 57.30, 71.58, and 83.17 respectively; F(1.133, 10.200) = 5.347, p < .05 (two-tailed).

Conclusions: The results showed that children’s developmental rates increased during a preschool EIBI program and following their graduation (post-EIBI periods) compared to pre-EIBI periods. Although statistically significant improvement in the Broad Independence standard scores was observed during both EIBI and post-EIBI periods, the changes were not clinically significant.

The findings begin to address the paucity of data on the long-term development of children with ASDs following EIBI.