Clinical trial results – A closer look under the surface

Published:January 28, 2020DOI:
      When reading the report of a clinical study in a medical journal, the typical question an overly busy clinician-reader asks is the following: do the results convince me and are they valid? In the era of evidence based medicine, the randomised clinical trial has become the reference-standard of all designs, when assessing the efficacy of a certain treatment or predefined diagnostic handling. This is because the comparison is based on random allocation of patients to the experimental arm or control arm of the trial, thereby preventing confounding by indication. Other mechanisms to further enhance the internal validity of randomized studies are concealment of allocation and blinding.
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        • Rennie D.
        Trial registration. a great idea switches from ignored to irresistible.
        JAMA. 2004; 292: 1359-1362
        • de Angelis C.
        • Drazen J.M.
        • Frizelle F.A.
        • Haug C.
        • Hoey J.
        • Horton R.
        • et al.
        Clinical trial registration: a statement from the international committee of medical journal editors.
        N Engl J Med. 2004; 351: 1250-1251
        • de Angelis C.D.
        • Drazen J.M.
        • Frizelle F.A.
        • Haug C.
        • Hoey J.
        • Horton R.
        • et al.
        Is this clinical trial fully registered? –A statement from the international committee of medical journal editors.
        N Engl J Med. 2005; 352: 2436-2438
        • Murad M.H.
        • Chu H.
        • Lin L.
        • Wang Z.
        The effect of publication bias magnitude and direction on the certainty in evidence.
        BMJ Evid Based Med. Jun 2018; 23: 84-86
      1. International Committee of Medical Journal Editors. Uniform requirements for manuscripts submitted to biomedical journals. Update posted on October 2005. Available

        • Moher D.
        • Schulz K.
        • Altman D.G.
        • for the CONSORT group
        The Consort statement: revised recommendations for improving the quality of reports of parallel-group randomised trials.
        Lancet. 2001; 357: 1191-1194
        • Ioannidis J.P.A.
        • Evans S.J.W.
        • Gotzsche P.C.
        • O'Neill R.T.
        • Altman D.G.
        • Schulz K.
        Better reporting of harms in randomized trials: an extension of the consort statement.
        Ann Intern Med. 2004; 141: 781-788
        • Egger M.
        • Jüni P.
        • Bartlett C.
        • for the CONSORT group
        Value of flow diagrams in reports of randomised controlled trials.
        JAMA. 2001; 285: 1996-1999
        • Moher D.
        • Jones A.
        • Lepage L.
        • for the CONSORT group
        Use of the consort statement and quality of reports of randomized trials: a comparative before and after evaluation.
        JAMA. 2001; 285: 1992-1995
        • Devereaux P.J.
        • Manns B.J.
        • Ghali W.A.
        • Quan H.
        • Guyatt G.H.
        The reporting of methodological factors in randomized controlled trials and the association with a journal policy to promote adherence to the consolidated standards of reporting trials (CONSORT) checklist.
        Control Clin Trials. 2002; 23: 380-388
        • Shepshelovich D.
        • Yahav D Tibau A.
        • Amir E.
        Assessment of frequency and reporting of design changes among clinical drug trials published in influential medical journals.
        Eur J Int Med. 2020; (in press)
        • Ridker P.M.
        • Torres J.
        Reported outcomes in major cardiovascular clinical trials funded by for profit and not-for-profit organizations: 2000-2005.
        JAMA. 2006; 295: 2270-2274
        • Colombel J.F.
        • Panaccione R.
        • Bossuyt P.
        • et al.
        Effect of tight control management on Crohn's disease (CALM): a multicentre, randomised, controlled phase 3 trial.
        Lancet. 2018; 390: 2779-2789
        • Connors J.M.
        • Jurczak W.
        • Straus D.J.
        • et al.
        Brentuximab Vedotin with chemotherapy for stage III or IV Hodgkin's Lymphoma.
        N Engl J Med. 2018; 378: 331-344
        • Eikelboom J.W.
        • Connolly S.J.
        • Bosch J.
        • et al.
        Rivaroxaban with or without aspirin in stable cardiovascular disease.
        N Engl J Med. 2017; 377: 1319-1330