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Commentary Advance Publication

Environ Health Perspect; DOI:10.1289/ehp.1307175

The Navigation Guide Systematic Review Methodology: A Rigorous and Transparent Method for Translating Environmental Health Science into Better Health Outcomes

Tracey J. Woodruff and Patrice Sutton
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Program on Reproductive Health and the Environment, University of California, San Francisco, Oakland, California, USA
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This EHP Advance Publication article has been peer-reviewed, revised, and accepted for publication. EHP Advance Publication articles are completely citable using the DOI number assigned to the article. This document will be replaced with the copyedited and formatted version as soon as it is available. Through the DOI number used in the citation, you will be able to access this document at each stage of the publication process.

Citation: Woodruff TJ , Sutton P. The Navigation Guide Systematic Review Methodology: A Rigorous and Transparent Method for Translating Environmental Health Science into Better Health Outcomes. Environ Health Perspect;

Received: 4 June 2013
Accepted: 24 February 2014
Advance Publication: 25 June 2014

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Background: Synthesizing what is known about the environmental drivers of health is instrumental to taking prevention-oriented action. Methods of research synthesis commonly used in environmental health lag behind systematic review methods developed in the clinical sciences over the past 20 years.

Objectives: Develop proof of concept of the “Navigation Guide,” a systematic and transparent method of research synthesis in environmental health.

Discussion: The Navigation Guide methodology builds on best practices in research synthesis in evidence-based medicine and environmental health. Key points of departure from current methods of expert-based narrative review prevalent in environmental health include: an a priori protocol; standardized and transparent documentation including expert judgment; a comprehensive search strategy; assessment of “risk of bias”; and separation of the science from values and preferences. Key points of departure from evidence-based medicine include: human observational studies were assigned a “moderate” quality rating; and diverse evidence streams were combined.

Conclusions: The Navigation Guide methodology is a systematic and rigorous approach to research synthesis that has been developed to reduce bias and maximize transparency in the evaluation of environmental health information. While novel aspects of the method will require further development and validation, our findings demonstrated that improved methods of research synthesis under development at the National Toxicology Program and under consideration by the U.S. Environmental Protection Agency are fully achievable. The institutionalization of robust methods of systematic and transparent review would provide a concrete mechanism for linking science to timely action to prevent harm.

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