Evidence hierarchies are widely used to assess evidence in systematic reviews of medical studies. I give several arguments against the use of evidence hierarchies. The problems with evidence hierarchies are numerous, and include methodological shortcomings, philosophical problems, and formal constraints. I argue that medical science should not employ evidence hierarchies, including even the latest and most-sophisticated of such hierarchies.
KeywordsEvidence Causality Evidence hierarchies Medicine Randomized trials Mechanisms Amalgamating evidence Quality assessment tools RCTs Meta-analysis
I am grateful to Phyllis Illari, Federica Russo, and two anonymous reviewers for detailed commentary on earlier drafts. Financial support was provided by the Banting Postdoctoral Fellowships program administered by the Social Sciences and Humanities Research Council of Canada.
- Borgerson K (2008) Valuing and evaluating evidence in medicine. PhD dissGoogle Scholar
- Cook TD, Campbell DT (1979) Quasi-experimentation: design and analysis issues for field settings. Houghton Mifflin, BostonGoogle Scholar
- Department of Clinical Epidemiology and Biostatistics, M. U. H. S. C (1981) How to read clinical journals: V: to distinguish useful from useless or even harmful therapy. Can Med Assoc J 124(9):1156–1162Google Scholar
- Karanicolas PJ, Kunz R, Guyatt GH (2008) Point: evidence-based medicine has a sound scientific base. [Editorial]. Chest 133(5):1067–1071. doi: 10.1378/chest.08-0068
- Rawlins M (2008) De Testimonio: on the evidence for decisions about the use of therapeutic interventions. Royal College of Physicians, LondonGoogle Scholar
- Stegenga J (forthcoming) Quality of information in clinical research. In: Illari PM, Floridi L (eds) The philosophy of information quality. SpringerGoogle Scholar
- Straus SE, Richardson WS, Glasziou PP, Haynes RB (2005) Evidence-based medicine: how to practice and teach, 3rd edn. Elsevier Churchill Livingstone, LondonGoogle Scholar
- Suppes P, Zinnes JL (1962) Basic measurement theory. Institute for mathematical studies in the social sciences, Technical Report No. 45Google Scholar
- Wilson MC, Hayward RS, Tunis SR, Bass EB, Guyatt G (1995) Users’ guides to the medical literature. VIII. How to use clinical practice guidelines. B. what are the recommendations and will they help you in caring for your patients? The evidence-based medicine working group. JAMA 274(20):1630–1632. doi: 10.1001/jama.1995.03530200066040 CrossRefGoogle Scholar