Handbook for Conducting Systematic Reviews for Health Effects Evaluations

The handbook provides standard operating procedures for conducting evidence evaluations using the OHAT Approach for Systematic Review and Evidence Integration. These procedures can be followed to develop evidence maps, scoping reports, or systematic reviews that identify the state-of-the science or reach hazard conclusions.

The handbook is a living document and is updated as methodological practices are refined and strategies are identified that improve the reliability, ease, and efficiency of conducting systematic reviews. NTP actively promotes methods development and harmonization of systematic review approaches with experts, organizations, and agencies conducting evidence evaluations in environmental health and toxicology.

Updates and clarifications to the handbook address two topics identified while conducting recent evidence evaluations: 1) the process for reaching hazard conclusions from human health data alone (i.e., in the absence of animal data or when there is low confidence in the available animal data), and 2) the process for developing confidence conclusions in the overall body of evidence across multiple outcomes, study types, or exposures.