On January 9, 2015 the U.S. National Toxicology Program’s (NTP) Office of Health Assessment and Translation (OHAT) published a handbook for the development of systematic reviews. OHAT uses such reviews for literature-based health assessments of environmental substances. The handbook is considered to be a “living document”. Therefore, it will be updated to reflect refinements to methodological practices.
U.S. NTP (January 9, 2015). “Handbook for conducting a literature-based health assessment using OHAT approach for systematic review and evidence integration.” (pdf)