Lay summary
Research suggests that 20 or more hours per week of intervention over several years may lead to significant improvements in long-term outcomes for young children with autism spectrum disorder (ASD). However, many families are unable to access or afford intensive early intervention. In these cases, it is possible that low-intensity intervention may be of some benefit. The early start Denver model (ESDM) is a promising intervention approach which has not been rigorously evaluated when implemented at a low-intensity. This proposed randomised controlled trial will evaluate the effectiveness of 2 hours a week of direct ESDM therapy and 30 min. to 1 hour a week of parent coaching for 6 months compared to treatment-as-usual for children with ASD between 12 and 60 months. The outcome measures will include child engagement, adaptive behaviour, cognitive abilities, and autism symptom severity. Effective low-intensity intervention approaches have the potential to significantly improve outcomes for individuals.