Intervention Effects of Intensity and Delivery Style for Toddlers With Autism

High quality, intensive early intervention is a powerful treatment for ASD, improving IQ and
language markedly in randomized controlled clinical trials (RCTs), though little long term
follow-up data exists. Few core characteristics that affect child change have been tested.
Two potential core characteristics that invoke considerable debate among parents,
professionals, and administrators are the delivery style of intervention: play-based versus
discrete trial teaching, and the intensity (dosage) of intervention. This ACE treatment
network will conduct two RCTs to answer two main questions: study 1: what are the effects of
intensity and delivery style on developmental progress of toddlers with ASD, and study 2: do
toddlers from a previous RCT of a specific intervention approach, the Early Start Denver
Model (ESDM), versus community treatment maintain and generalize treatment effects over 3
years?

A sample of 108 young children with ASD, ages 15-30 months who live within a specified radius
near the university at each site will be enrolled in one of three national sites (Univ Cal
Davis, Vanderbilt, Univ. Washington) and randomized into one of four cells varying on two
dimensions: dosage - 15 or 25 hours per week of 1:1 treatment; and discrete trial teaching or
play and routines- based teaching. Other aspects of intervention will be held constant: use
of the principles of applied behavior analysis, intensity, parent coaching in the assigned
treatment, and location. Developmental progress will be measured monthly allowing for growth
curve analysis to examine fine-grained differences in groups as well as interactions among
major child and family initial variables and these two experimental variables.

Inclusion Criteria:

1.15-30 months of age 2. Ambulatory and without primary motor impairments affecting hand
use 3. meets criteria for Autistic Spectrum Disorder using DSM-5 criteria 4. clinical
consensus of diagnosis by 2 independent staff, one of whom is a licensed psychologist based
on observation as well as record review 6. meets autism cutoff on the Autism Diagnostic
Observation Schedule for Toddlers (ADOS - T; Luyster et al, 2009) 7. confidence rating
assigned by assessor as relatively confident or very confident in diagnosis.

8. Overall developmental quotient of 35 or higher on Mullen Scales of Early Learning
(Mullen, 1995) 9. Parental agreement to complete project materials, to participate in
parent coaching twice per month at home, to have therapy assistants in the home 15-25 hours
per week, to attend a clinic meeting twice each month and to videotape regularly at home
with project provided equipment 10. English as a primary language spoken to the child (60%
or more at home as reported by parents), 11. Attendance at all initial evaluation sessions,
and no more than 1 failure to keep appointments without calling to cancel during the intake
period 12. Hearing and vision screen within the normal range. 13. Lives within a specified
radius close to the university (the specific mileage varies somewhat for each site.)

Exclusion Criteria:

1. Children who have been receiving 10 hours per week of intensive, curriculum-based
therapy for more than 1 month

2. Families who miss 2 or more consecutive appointments without previous notification