Research Pearls: How Do We Establish the Level of Evidence?


      Evidence-based medicine (EBM) guidelines were first introduced in 1986 and were defined as the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of EBM means integrating individual clinical expertise with the best available external clinical evidence from systematic research. Level of evidence (LOE) stratifies publications from Level I to Level V and provides the foundation for EBM. Three questions should be asked when an LOE is assigned to a scientific article: (1) What is the research question? (2) What is the study type? and (3) What is the hierarchy of evidence? In cases in which LOE is not appropriate or relevant (basic science and laboratory-based investigations), a clinical relevance statement should be used. Unfortunately, study quality is not assessed by the assigned hierarchy level. LOE and EBM have increased the number of investigations published with better levels of evidence. As authors, reviewers, editors, and publishers, we desire a system that is consistent, effective, and reliable. Fortunately, the system has proven to have all of those attributes with good interobserver and intra-observer values. The increase in investigations with higher LOEs allows for more frequent use of EBM.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Arthroscopy
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Sackett D.L.
        Rules of evidence and clinical recommendations on the use of antithrombotic agents.
        Chest. 1986; 89: 2S-3S
        • Wright J.G.
        • Swiontkowski M.F.
        • Heckman J.D.
        Introducing levels of evidence to the journal.
        J Bone Joint Surg Am. 2003; 85: 1-3
        • Marx R.G.
        • Wilson S.M.
        • Swiontkowski M.F.
        Updating the assignment of levels of evidence.
        J Bone Joint Surg Am. 2015; 97: 1-2
        • Lubowitz J.H.
        Understanding evidence-based arthroscopy.
        Arthroscopy. 2004; 20: 1-3
        • Sackett D.L.
        • Rosenberg W.M.
        • Gray J.A.
        • Haynes R.B.
        • Richardson W.S.
        Evidence based medicine: What it is and what it isn't.
        BMJ. 1996; 312: 71-72
        • Obremskey W.T.
        • Pappas N.
        • Attallah-Wasif E.
        • Tornetta 3rd, P.
        • Bhandari M.
        Level of evidence in orthopaedic journals.
        J Bone Joint Surg Am. 2005; 87: 2632-2638
        • Hussain N.
        • Yankanah R.
        • Wright J.G.
        The validity of level of evidence ratings of articles submitted to JBJS.
        J Bone Joint Surg Am. 2015; 97: e8
        • Kane R.L.
        • Wang J.
        • Garrard J.
        Reporting in randomized clinical trials improved after adoption of the CONSORT statement.
        J Clin Epidemiol. 2007; 60: 241-249
        • Dulai S.K.
        • Slobogean B.L.
        • Beauchamp R.D.
        • Mulpuri K.
        A quality assessment of randomized clinical trials in pediatric orthopaedics.
        J Pediatr Orthop. 2007; 27: 573-581
        • Berwanger O.
        • Ribeiro R.A.
        • Finkelsztejn A.
        • et al.
        The quality of reporting of trial abstracts is suboptimal: Survey of major general medical journals.
        J Clin Epidemiol. 2009; 62: 387-392
        • Poolman R.W.
        • Struijs P.A.
        • Krips R.
        • Sierevelt I.N.
        • Lutz K.H.
        • Bhandari M.
        Does a "Level I Evidence" rating imply high quality of reporting in orthopaedic randomised controlled trials?.
        BMC Med Res Methodol. 2006; 6: 44
        • Guyatt G.H.
        • Oxman A.D.
        • Vist G.E.
        • et al.
        GRADE: An emerging consensus on rating quality of evidence and strength of recommendations.
        BMJ. 2008; 336: 924-926
        • Higgins J.P.T.
        • Green S.
        • eds
        Cochrane handbook for systematic reviews of interventions. Version 5.1.9 [updated March 2011]. The Cochrane Collaboration.
        (Accessed May 18, 2018)
        • Wright J.G.
        A practical guide to assigning levels of evidence.
        J Bone Joint Surg Am. 2007; 89: 1128-1130
        • Viele K.
        • Berry S.
        • Neuenschwander B.
        • et al.
        Use of historical data for assessing treatment effects in clinical trials.
        Pharm Stat. 2014; 13: 41-54
        • Galwey N.W.
        Supplementation of a clinical trial by historical control data: Is the prospect of dynamic borrowing an illusion?.
        Stat Med. 2017; 36: 899-916
        • Hohmann E.
        • Brand J.C.
        • Rossi M.J.
        • Lubowitz J.H.
        Expert opinion is necessary: Delphi Panel Methodology facilitates a scientific approach to consensus.
        Arthroscopy. 2018; 34: 349-351
        • Hohmann E.
        • Cote M.
        • Brand J.C.
        Research pearls: expert consensus based evidence using the Delphi method.
        Arthroscopy. 2018; 34: 3278-3282
        • Cunningham B.P.
        • Harmsen S.
        • Kweon C.
        • et al.
        Have levels of evidence improved the quality of orthopaedic research?.
        Clin Orthop Relat Res. 2013; 471: 3679-3686
        • Bhandari M.
        • Swiontkowski M.F.
        • Einhorn T.A.
        • et al.
        Interobserver agreement in the application of levels of evidence to scientific papers in the American volume of the Journal of Bone and Joint Surgery.
        J Bone Joint Surg Am. 2004; 86: 1717-1720
        • Hasan K.
        • Shankar S.
        • Sharma A.
        • et al.
        Hip surgery and its evidence base: Progress over a decade?.
        J Orthop Traumatol. 2016; 17: 291-295
        • Amiri A.R.
        • Kanesalingam K.
        • Cro S.
        • Casey A.T.
        Does source of funding and conflict of interest influence the outcome and quality of spinal research?.
        Spine J. 2014; 14: 308-314