Evaluation of an Early Start Denver Model-based intervention for young children with autism in an inclusive preschool setting.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by difficulties in social communication and the presence of restricted or repetitive behaviours or interests. There is evidence to suggest that early intervention (EI) can lead to improved outcomes for children with ASD. Inclusive preschool-based delivery of EI appears to satisfy current legal and best-practice recommendations around the delivery of EI for young children with ASD. It may also offer several potential benefits including cost-effectiveness, efficiency and opportunities for children with ASD to learn from their peers. The Early Start Denver Model (ESDM) is a promising naturalistic behavioural developmental intervention for young children with ASD aged between 12 and 60 months. The ESDM can be delivered to children in a group-based format and several studies have demonstrated its effectiveness when delivered for 15 to 25 hours per week in designated ESDM preschools with low child–teacher ratios. However, the preschools involved in these studies may not be representative of the typical preschool setting for many communities. Thus, more research is needed to determine the effectiveness of this intervention when delivered under conditions that more closely reflect the typical real-world preschool setting. In the present thesis, two studies with multiple probe across participants designs, each involving three preschool children with ASD, examined the feasibility and effectiveness of the use of the ESDM in an inclusive preschool setting. Specifically, Study 1 evaluated the effectiveness of a modified version of ESDM therapy delivered by a certified therapist and Study 2 evaluated (a) the effectiveness of a brief ESDM coaching programme, and (b) the effectiveness of a modified version of ESDM therapy delivered by preschool teachers. For both studies, the intervention was delivered in regular community preschools and no major changes were made to the typical preschool environments or routines. Effectiveness was assessed by measuring improvements in child active participation, vocal/verbal communication and imitation, and, for Study 2, teachers’ fidelity of implementation of ESDM techniques. Teachers’ perceptions of the acceptability and effectiveness of the intervention were also assessed via a questionnaire and in-depth interviews. In Study 1, an outside certified therapist delivered 3 hours per week of ESDM to three children with ASD over an 8- to 10-week period. Participants showed improvement in active participation, imitation and either intentional vocalisations or spontaneous functional utterances. These results were generally maintained at follow-up. For Study 2, a brief coaching programme was used to train three preschool teachers to use the ESDM with a child with ASD who attended the inclusive preschools where they worked. Teachers improved in their use of the ESDM strategies and children demonstrated improved levels of active participation but results for child imitation and communication were mixed. Teachers also found the intervention to be acceptable and effective. Together, the results from these studies provide preliminary support for the feasibility and effectiveness of the ESDM when delivered in real-world inclusive preschool settings. More research is needed to determine the most effective approach to delivering EI for ASD in an inclusive preschool setting. It may also be valuable to evaluate the extent to which gains made by children and teachers during intervention generalise to other people and/or settings.