Two Year Outcome and Developmental Progress of Toddlers with Autism Spectrum Disorders (ASD) Receiving Early Intervention

Background: Intensive treatment in toddlers with ASD is associated with clinical improvement. However, in clinical practice, we sometimes see toddlers receiving little therapy make progress while others receiving intensive therapy make less progress

Objectives: We compared the developmental progress of toddlers with ASD receiving variable hours of treatment over 2 years.

Methods: Seventeen children with an ASD, ages 26 and 32 months, were followed every 6 months for 2 years. All received baseline assessments with the Autism Diagnostic Observation Schedule (ADOS), Mullen Scales of Early Learning (MSEL), Vineland Adaptive Behavior Scales (VABS) and Pervasive Developmental Disorders Behavior Inventory (PDDBI) . Intensive treatment at 20 hours a week was recommended for all. At follow-up, all received the MSEL, VABS, PDDBI and ADOS.

Results:  3 girls and 14 boys with mean age of 28.8 months were followed for 2 years. At baseline assessment, 10 met criteria for Autism and 7 for PDD,NOS on the ADOS; This table shows the mean scores and range of the Early Learning Composite (ELC) scores on the MSEL,the PDDBI autism index T-scores and Behavior Adaptive Composite Scores (ABC)at baseline and at 2 years follow-up.

At the 2-year follow-up:  Three children changed ASD diagnoses: 2 from Autism to PDD,NOS and one lost his ASD diagnosis .  

 

	Baseline Mean scores (Range)	2 years Follow-up Mean Scores (Range)
MSEL	72.2  (49-111)	86    (49-150)
PDDBI Autism Index scores	46.8  (36-61)	37.9 (18-67)
VABS	78.8  (58-93)	85.8 (50-109)

Positive trends, indicating improvement, were observed on all scores in all children. No significant correlation (r=0.02; p=0.93) was found between cumulative total number of hours and change scores on the ELC, ABC, Autism index scores, or the ADOS scores using the Spearman Corelation test. Individual baseline visual motor scores on the MSEL were found to correlate significantly with ADOS change scores (r=0.6;p=0.009). 

Conclusions:  These data suggest that greater intensity of treatment does not necessarily lead to more clinical improvement in toddlers with ASD. Further data collection with larger samples is needed and is underway to better clarify these associations and to identify the elements that are important in treatment response.