Protocol for a systematic evidence map of environmental research related to autism spectrum disorders: the aWARE...

Emerging data supporting the potential contribution of environmental chemical exposures to the etiology of autism spectrum disorders (ASD) led to increased interest, research, and publications. This diverse and rapidly growing body of evidence covers a range of study designs, environmental exposures, and ASD-related outcomes. The amount and complexity of research present barriers to identifying, characterizing, and synthesizing relevant evidence to better understand potential associations. The objective of this protocol is to describe a systematic evidence map (SEM) method for identifying and characterizing published scientific research on early-life environmental chemical and physical exposures and ASD or ASD-related outcomes into an interactive resource called aWARE - a Web-based tool for Autism Research and the Environment.

A comprehensive search for ASD-related studies will be conducted in PubMed, Web of Science, and Scopus, without limits on publication year or language. Eligibility criteria focused on early-life environmental exposure will guide the selection of relevant articles using DistillerSR® and study characteristics will be extracted using DEXTR, a web-based semi-automated data extraction software. Studies will be categorized based on key concepts including major categories of exposure (e.g., air pollution), evidence stream (human, experimental animal), study design, and ASD outcomes, and visualized as SEMs in aWARE, a queryable and interactive database created using Tableau. Input from the autism community will be used to guide the scope of this project and format of the SEMs to increase the utility of the tool. The results of the SEMs will also be summarized in a brief narrative format.

This protocol reports pre-specified SEM methods for developing the aWARE tool on ASD and environmental exposures including outreach to the autism community for important input. The resulting project will advance ASD research with the protocol ensuring transparency and replicability.