HAH-15-006 We have created a unique 5-level Autism Classification System of Functioning: Social Communication (ACSF:SC) for use with children with Autism (ASD). HAHSO Funds enabled us to begin to recruit families and clinicians, to compare parent ACSF:SC ratings with clinicians’ gold standard ADOS ASD assessments. These paired data are being used to create an algorithm to enable us to `harvest’ an ACSF:SC from prior ADOS data. In 2016, we published a poster on the feasibility of algorithm development. In 2017, we created a video introduction of the ACSF:SC for families and professionals. In 2018, our second poster outlined our findings from this initial algorithm work. Our plan is to use the longitudinal Canadian Pathways study data to examine children’s abilities over time.

HAH-15-006 Introduction: Our new ACSF:SC classifies 5 levels of social communication abilities of children with ASD, assessing both children’s Typical Performance and Best Capacity. The ACSF:SC works with preschool children (3 to <6 years), and we now want to know if it can work with toddlers (<3 years) and school-aged children (≥6 years) by assessing its content validity. We are holding group discussions and interviews with professionals and families to explore if/how we need to adjust the level descriptions to reflect abilities of younger and older children. Next, we will invite families and professionals to test the expanded versions of the ACSF:SC with their toddlers and school-aged children, so we can classify abilities of children with autism from diagnosis and as they grow up. Methods: Using mixed-methods, we conducted cognitive interviews and focus groups with parents and clinicians, and analyzed transcripts qualitatively. Results: Ten parents and 17 clinicians working with toddlers or school-aged children with ASD participated, and three themes emerged: applicability (developmental appropriateness of the level descriptions); clarity (respondents’ understanding of the ACSF:SC, its explicit and underlying constructs, level descriptions and distinctions); and usability (helping us to identify areas that needed to be more user-friendly language). Conclusion: Through various validation processes, these results indicated that ACSF:SC constructs were applicable to both toddlers and school-aged children with ASD, as well as being understood by most parents. Several recommendations have been integrated into the revised ACSF:SC, called “ACSF:SC –Integrated”. Reliability field testing is currently underway at the time of submission and results will be shared at the presentation.