Effects of a low-intensity Early Start Denver Model-based intervention delivered in an inclusive preschool setting

The Early Start Denver Model (ESDM) is a promising early intervention for promoting improved social, cognitive, and communication outcomes for young children with autism spectrum disorder (ASD). However, most studies evaluating group-based delivery of this program have used 15-25 h per week of intervention in specialized ESDM preschools with low child-teacher ratios. Thus, the positive results from such studies might not be obtained when this intervention model is evaluated in more typical inclusive preschool settings. In this study, a low-intensity version of the ESDM was delivered to three young children with ASD in their regular inclusive preschool by a certified therapist who did not typically work at any of the preschools. The intervention procedures were implemented for 3 h per week over an 8- to 10-week period. Data were gathered on children's levels of participation, imitation, and communication from weekly 10-min video recordings. The effects of the intervention were evaluated using a multiple probe across participants design with 3 weekly follow-up probes, 3 weeks after the intervention ended. All participants showed improvement in active participation, imitation and either intentional vocalizations or spontaneous functional utterances. These results were generally maintained at follow-up. This low-intensity version of the ESDM would seem effective for use in real-world preschool environments.