Are review articles a reliable source of evidence to support conservation and environmental management? A comparison with medicine

Review articles are important sources of information and often the only source of evidence used by decision makers in conservation and environmental management to assess effectiveness and impact of interventions and other actions. Recent developments in the field of medicine and public health have established ‘systematic review’ guidelines to minimise bias and explicitly document methodology, allowing replication and updating in light of further advances. The aim of this article was to assess the methodological and reporting rigour of reviews from the disciplines of conservation, ecology and environmental management (referred to as “ecological reviews”). This was achieved by comparing them to medical systematic reviews, using 27 detailed criteria well established in medicine. When compared with medical systematic reviews, ecological reviews were more likely to be prone to bias, lacking details in the methods used to search for studies, and were less likely to assess the relevance of studies, quality of the original experiments and to quantitatively synthesise the evidence. Overall, ecological reviews show lower quality and greater variation in reporting style and review methods. To address this, reviewers could use a systematic review approach and journals could provide more explicit guidelines for the preparation and production of review articles.