The reliability of evidence review methodology in environmental science and conservation

Bethan C. O'Leary*, Kristian Kvist, Helen R. Bayliss, Géraldine Derroire, John R. Healey, Kathryn Hughes, Fritz Kleinschroth, Marija Sciberras, Paul Woodcock, Andrew S. Pullin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Citations (Scopus)
54 Downloads (Pure)


Given the proliferation of primary research articles, the importance of reliable environmental evidence reviews for informing policy and management decisions is increasing. Although conducting reviews is an efficient method of synthesising the fragmented primary evidence base, reviews that are of poor methodological reliability have the potential to misinform by not accurately reflecting the available evidence base. To assess the current value of evidence reviews for decision-making we appraised a systematic sample of articles published in early 2015 (N = 92) using the Collaboration for Environmental Evidence Synthesis Assessment Tool (CEESAT). CEESAT assesses the methodology of policy-relevant evidence reviews according to elements important for objectivity, transparency and comprehensiveness. Overall, reviews performed poorly with a median score of 2.5/39 and a modal score of zero (range 0–30, mean 5.8), and low scores were ubiquitous across subject areas. In general, reviews that applied meta-analytical techniques achieved higher scores than narrative syntheses (median 18.3 and 2.0 respectively), as a result of the latter consistently failing to adequately report methodology or how conclusions were drawn. However, some narrative syntheses achieved high scores, illustrating that the reliability of reviews should be assessed on a case-by-case basis. Given the potential importance of reviews for informing management and policy, as well as research, it is vital that overall methodological reliability is improved. Although the increasing number of systematic reviews and meta-analyses highlight that some progress is being made, our findings suggest little or no improvement in the last decade. To motivate progress, we recommend that an annual assessment of the methodological reliability of evidence reviews be conducted. To better serve the environmental policy and management communities we identify a requirement for independent critical appraisal of review methodology thus enabling decision-makers to select reviews that are most likely to accurately reflect the evidence base.

Original languageEnglish
Pages (from-to)75-82
Number of pages8
JournalEnvironmental Science and Policy
Early online date1 Jul 2016
Publication statusPublished - Oct 2016


  • Decision-making
  • Evidence syntheses
  • Evidence-base
  • Review evaluation
  • Review methodology

ASJC Scopus subject areas

  • Geography, Planning and Development
  • Management, Monitoring, Policy and Law


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