Early intervention for young children with autism spectrum disorder: protocol for a scoping review of economic evaluations

Background: In many countries, children who are diagnosed with autism during the first 5 years of life are offered a range of early intervention options. These options vary considerably in the theoretical approaches and techniques applied, their intensity and duration, settings, the person/s delivering supports and the training they require. Early interventions are a significant contributor to total autism-related costs in Western countries, but only in the last 10–20 years has there been adequate outcome data to enable the comparison of different interventions’ cost-effectiveness. This protocol describes a scoping review to better understand what economic evaluations have been completed in this field, and the methods used to date. Methods: We will systematically search the following databases from their inception to 2021 for eligible studies: MEDLINE, EMBASE, PsycINFO, Econlit, PEDE, NHS EED and HTA. Full economic evaluations of any types of early intervention for children with autism prior to school entry will be included. Two reviewers will screen the studies, extract the data and assess the study quality using established checklists. The risk of bias will be assessed using the extended CHEC-list for all studies and, additionally, the Philips checklist for modelled studies. Quality of reporting will be assessed using the CHEERS checklist. A narrative synthesis will be completed to collate the findings, describe the methods used and identify which interventions have been researched from an economic perspective. Discussion: This review will provide researchers, policymakers and service providers with current information about the economic evidence for early interventions for young children with autism and point to priorities for further research. It will inform future economic evaluations by highlighting the gaps or inconsistencies in the methods used to date. Limitations of the review will be acknowledged and discussed. Systematic review registration: Open Science Framework: https://osf.io/sj7kt.