Identifying and measuring the common elements of naturalistic developmental behavioral interventions for autism spectrum disorder: Development of theNDBI-Fi

Naturalistic developmental behavioral interventions for young children with autism spectrum disorder share key elements. However, the extent of similarity and overlap in techniques among naturalistic developmental behavioral intervention models has not been quantified, and there is no standardized measure for assessing the implementation of their common elements. This article presents a multi-stage process which began with the development of a taxonomy of elements of naturalistic developmental behavioral interventions. Next, intervention experts identified the common elements of naturalistic developmental behavioral interventions using quantitative methods. An observational rating scheme of those common elements, the eight-itemNDBI-Fi, was developed. Finally, preliminary analyses of the reliability and the validity of theNDBI-Fiwere conducted using archival data from randomized controlled trials of caregiver-implemented naturalistic developmental behavioral interventions, including 87 post-intervention caregiver-child interaction videos from five sites, as well as 29 pre-post video pairs from two sites. Evaluation of the eight-itemNDBI-Fimeasure revealed promising psychometric properties, including evidence supporting adequate reliability, sensitivity to change, as well as concurrent, convergent, and discriminant validity. Results lend support to the utility of theNDBI-Fias a measure of caregiver implementation of common elements across naturalistic developmental behavioral intervention models. With additional validation, this unique measure has the potential to advance intervention science in autism spectrum disorder by providing a tool which cuts across a class of evidence-based interventions. Lay abstract Naturalistic developmental behavioral interventions for young children with autism spectrum disorder share key elements. However, the extent of similarity between programs within this class of evidence-based interventions is unknown. There is also currently no tool that can be used to measure the implementation of their common elements. This article presents a multi-stage process which began with defining all intervention elements of naturalistic developmental behavioral interventions. Next, intervention experts identified the common elements of naturalistic developmental behavioral interventions using a survey. An observational rating scheme of those common elements, the eight-itemNDBI-Fi, was developed. We evaluated the quality of theNDBI-Fiusing vid