title: The Navigation Guide - evidence-based medicine meets environmental health: integration of animal and human evidence for PFOA effects on fetal growth.
abstract: BACKGROUND
  The Navigation Guide is a novel systematic review method to synthesize scientific evidence and reach strength of evidence conclusions for environmental health decision making.
  
  
  OBJECTIVE
  Our aim was to integrate scientific findings from human and nonhuman studies to determine the overall strength of evidence for the question "Does developmental exposure to perfluorooctanoic acid (PFOA) affect fetal growth in humans?"
  
  
  METHODS
  We developed and applied prespecified criteria to systematically and transparently a) rate the quality of the scientific evidence as "high," "moderate," or "low"; b) rate the strength of the human and nonhuman evidence separately as "sufficient," "limited," "moderate," or "evidence of lack of toxicity"; and c) integrate the strength of the human and nonhuman evidence ratings into a strength of the evidence conclusion.
  
  
  RESULTS
  We identified 18 epidemiology studies and 21 animal toxicology studies relevant to our study question. We rated both the human and nonhuman mammalian evidence as "moderate" quality and "sufficient" strength. Integration of these evidence ratings produced a final strength of evidence rating in which review authors concluded that PFOA is "known to be toxic" to human reproduction and development based on sufficient evidence of decreased fetal growth in both human and nonhuman mammalian species.
  
  
  CONCLUSIONS
  We concluded that developmental exposure to PFOA adversely affects human health based on sufficient evidence of decreased fetal growth in both human and nonhuman mammalian species. The results of this case study demonstrate the application of a systematic and transparent methodology, via the Navigation Guide, for reaching strength of evidence conclusions in environmental health.
authors: Oak Ridge Institute for Science and Education (ORISE) Postdoctoral Fellow, National Center for Environmental Economics, Office of Policy, U.S. Environmental Protection Agency, Washington, DC, USA.
authors: Juleen
authors: J
authors: Lam
authors: Erica
authors: E
authors: Koustas
authors: Patrice
authors: P
authors: Sutton
authors: Paula I
authors: PI
authors: Johnson
authors: Dylan S
authors: DS
authors: Atchley
authors: Saunak
authors: S
authors: Sen
authors: Karen A
authors: KA
authors: Robinson
authors: Daniel A
authors: DA
authors: Axelrad
authors: Tracey J
authors: TJ
authors: Woodruff
mesh_terms: D000818:Animals; D001724:Birth Weight / Q000187:drug effects; D002210:Caprylates / Q000633:toxicity*; D004782:Environmental Health; D004785:Environmental Pollutants / Q000633:toxicity*; D019317:Evidence-Based Medicine; D005260:Female; D047109:Fetal Development / Q000187:drug effects*; D005466:Fluorocarbons / Q000633:toxicity*; D006801:Humans; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy
chemical_list: D002210:Caprylates; D004785:Environmental Pollutants; D005466:Fluorocarbons; C023036:perfluorooctanoic acid