Dimensional Assessment of Restricted and Repetitive Behaviors: Development and Preliminary Validation of a New Measure

Objective: This study aimed to provide initial validation of the Dimensional Assessment of Restricted and Repetitive Behaviors (DARB), a new parent-report measure designed to capture the full range of key restricted and repetitive behaviors (RRB) subdomains.Method: Parents of 1,892 children and adolescents with autism spectrum disorder (mean [SD] age 1/4 10.81 [4.14] years) recruited from the SPARK (Simons Foundation Powering Autism Research for Knowledge) research match completed the DARB, several existing RRB instruments, and measures of social and communication impairments and anxiety. A subsample of 450 parents completed the DARB after 2 weeks to evaluate the test-retest stability.Results: Exploratory graph analysis conducted in the exploratory subsample identified 8 dimensions that were aligned with hypothesized RRB subdomains: repetitive sensory motor behaviors, insistence on sameness, restricted interests, unusual interests, sensory sensitivity, self-injurious behaviors, obsessions and compulsive behaviors, and repetitive language. The confirmatory application of the exploratory structural equation modeling conducted in the confirmatory subsample showed that the derived factor structure had a good fit to the data. Derived factors had excellent reliability, convergent and divergent validity, and very strong test-retest stability and showed a distinct pattern of associations with key demographic, cognitive and clinical correlates.Conclusion: The DARB will be useful in a variety of research and clinical contexts considering the prominence and clinical impact of RRB in autism spectrum disorder. Strong preliminary evidence indicates that the new scale is comprehensive and captures a wide range of distinct RRB subdomains not simultaneously captured by any of the existing instruments.