CONSORT and Its Extensions for Reporting Clinical Trials

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Principles and Practice of Clinical Trials

Abstract

Well-designed and properly executed randomized controlled trials provide the most reliable evidence on the efficacy of healthcare interventions. However, there is overwhelming evidence that the quality of reporting of randomized trials is not always optimal. Without transparent reporting, readers cannot judge the reliability and validity of trial findings nor extract information for systematic reviews. Trials with inadequate methods are also associated with bias, especially exaggerated treatment effects (Savovic et al. 2012; Wood et al. 2008). Critical appraisal of the quality of clinical trials is only possible if the design, conduct, and analysis of randomized trials are thoroughly and accurately reported. The CONSORT (CONsolidated Standards of Reporting Trials) statement is comprised of a checklist of essential items that should be included in reports of randomized controlled trials and a diagram documenting the flow of participants through a trial. The objective of CONSORT is to provide guidance to authors about how to improve the reporting of their trials and ensure trial reports are clear, complete, and transparent (Moher et al. 2010a; Schulz et al. 2010a). Readers, peer reviewers, and editors can also use CONSORT to help them interpret the reports of randomized trials. CONSORT is not meant to be used as a quality assessment instrument, rather, the content of CONSORT relates to the internal and external validity of trials. Many items not explicitly mentioned in CONSORT may also be included in a report, such as information about approval by an ethics committee, informed consent from participants, and, where relevant, existence of a data and safety monitoring committee. The CONSORT statement thus addresses the minimum trial reporting criteria and should not deter authors from including other information they consider important (Moher et al. 2010a).

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References

  • Altman DG, Schulz KF, Moher D, Egger M, Davidoff F, Elbourne D et al (2001) The revised CONSORT statement for reporting randomized trials: explanation and elaboration. Ann Intern Med 134(8):663–694

    Article  Google Scholar 

  • Barnes C, Boutron I, Giraudeau B, Porcher R, Altman DG, Ravaud P (2015) Impact of an online writing aid tool for writing a randomized trial report: the COBWEB (Consort-based WEB tool) randomized controlled trial. BMC Med 13:221

    Article  Google Scholar 

  • Begg C, Cho M, Eastwood S, Horton R, Moher D, Olkin I et al (1996) Improving the quality of reporting of randomized controlled trials. The CONSORT statement. JAMA 276(8):637–639

    Article  Google Scholar 

  • Blanco D, Biggane AM, Cobo E (2018) Are CONSORT checklists submitted by authors adequately reflecting what information is actually reported in published papers? Trials 19(1):80

    Article  Google Scholar 

  • Boutron I, Altman DG, Moher D, Schulz KF, Ravaud P (2017) CONSORT statement for randomized trials of nonpharmacologic treatments: a 2017 update and a CONSORT extension for nonpharmacologic trial abstracts. Ann Intern Med 167(1):40–47

    Article  Google Scholar 

  • Calvert M, Blazeby J, Altman DG, Revicki DA, Moher D, Brundage MD (2013) Reporting of patient-reported outcomes in randomized trials: the CONSORT PRO extension. JAMA 309(8):814–822

    Article  Google Scholar 

  • Campbell MK, Piaggio G, Elbourne DR, Altman DG (2012) Consort 2010 statement: extension to cluster randomised trials. BMJ (Clin Res Ed) 345:e5661

    Google Scholar 

  • Chauvin A, Ravaud P, Baron G, Barnes C, Boutron I (2015) The most important tasks for peer reviewers evaluating a randomized controlled trial are not congruent with the tasks most often requested by journal editors. BMC Med 13:158

    Article  Google Scholar 

  • Chauvin A, Moher D, Altman D, Schriger DL, Alam S, Hopewell S et al (2017) A protocol of a cross-sectional study evaluating an online tool for early career peer reviewers assessing reports of randomised controlled trials. BMJ Open 7(9):e017462

    Article  Google Scholar 

  • Cheng CW, Wu TX, Shang HC, Li YP, Altman DG, Moher D et al (2017) CONSORT extension for Chinese herbal medicine formulas 2017: recommendations, explanation, and elaboration. Ann Intern Med 167(2):112–121

    Article  Google Scholar 

  • Dimairo M, Coates E, Pallmann P, Todd S, Julious SA, Jaki T et al (2018) Development process of a consensus-driven CONSORT extension for randomised trials using an adaptive design. BMC Med 16(1):210

    Article  Google Scholar 

  • Dwan K, Li T, Altman DG, Elbourne D (2019) CONSORT 2010 statement: extension to randomised crossover trials. BMJ (Clin Res ed) 366:l4378

    Google Scholar 

  • Eldridge SM, Chan CL, Campbell MJ, Bond CM, Hopewell S, Thabane L et al (2016a) CONSORT 2010 statement: extension to randomised pilot and feasibility trials. BMJ (Clin Res Ed) 355:i5239

    Google Scholar 

  • Eldridge SM, Chan CL, Campbell MJ, Bond CM, Hopewell S, Thabane L et al (2016b) CONSORT 2010 statement: extension to randomised pilot and feasibility trials. Pilot Feasibility Stud 2:64

    Article  Google Scholar 

  • Gabriel SE, Normand SL (2012) Getting the methods right – the foundation of patient-centered outcomes research. N Engl J Med 367(9):787–790

    Article  Google Scholar 

  • Gagnier JJ, Boon H, Rochon P, Moher D, Barnes J, Bombardier C (2006) Reporting randomized, controlled trials of herbal interventions: an elaborated CONSORT statement. Ann Intern Med 144(5):364–367

    Article  Google Scholar 

  • Hopewell S, Clarke M, Moher D, Wager E, Middleton P, Altman DG et al (2008a) CONSORT for reporting randomized controlled trials in journal and conference abstracts: explanation and elaboration. PLoS Med 5(1):e20

    Article  Google Scholar 

  • Hopewell S, Clarke M, Moher D, Wager E, Middleton P, Altman DG et al (2008b) CONSORT for reporting randomised trials in journal and conference abstracts. Lancet (London) 371(9609):281–283

    Article  Google Scholar 

  • Hopewell S, Dutton S, Yu LM, Chan AW, Altman DG (2010) The quality of reports of randomised trials in 2000 and 2006: comparative study of articles indexed in PubMed. BMJ (Clin Res Ed) 340:c723

    Article  Google Scholar 

  • Hopewell S, Hirst A, Collins GS, Mallett S, Yu LM, Altman DG (2011) Reporting of participant flow diagrams in published reports of randomized trials. Trials 12:253

    Article  Google Scholar 

  • Hopewell S, Ravaud P, Baron G, Boutron I (2012) Effect of editors’ implementation of CONSORT guidelines on the reporting of abstracts in high impact medical journals: interrupted time series analysis. BMJ (Clin Res Ed) 344:e4178

    Google Scholar 

  • Hopewell S, Collins GS, Boutron I, Yu LM, Cook J, Shanyinde M et al (2014) Impact of peer review on reports of randomised trials published in open peer review journals: retrospective before and after study. BMJ (Clin Res Ed) 349:g4145

    Google Scholar 

  • Hopewell S, Boutron I, Altman DG, Barbour G, Moher D, Montori V et al (2016) Impact of a web-based tool (WebCONSORT) to improve the reporting of randomised trials: results of a randomised controlled trial. BMC Med 14(1):199

    Article  Google Scholar 

  • Ioannidis JP, Evans SJ, Gotzsche PC, O’Neill RT, Altman DG, Schulz K et al (2004) Better reporting of harms in randomized trials: an extension of the CONSORT statement. Ann Intern Med 141(10):781–788

    Article  Google Scholar 

  • Juszczak EA, Altman DG, Hopewell S, Schulz K (2019) Reporting of multi-arm parallel group randomized trials: extension of the CONSORT 2010 statement. JAMA 321(16):1610–1620

    Article  Google Scholar 

  • Kwakkenbos L, Juszczak E, Hemkens LG, Sampson M, Frobert O, Relton C et al (2018) Protocol for the development of a CONSORT extension for RCTs using cohorts and routinely collected health data. Res Integr Peer Rev 3:9

    Article  Google Scholar 

  • MacPherson H, Altman DG, Hammerschlag R, You** L, Taixiang W, White A et al (2010) Revised Standards for reporting interventions in clinical trials of acupuncture (STRICTA): extending the CONSORT statement. PLoS Med 7(6):e1000261

    Article  Google Scholar 

  • Moher D, Schulz KF, Altman D (2001) The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials. JAMA 285(15):1987–1991

    Article  Google Scholar 

  • Moher D, Hopewell S, Schulz KF, Montori V, Gotzsche PC, Devereaux PJ et al (2010a) CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. BMJ (Clin Res Ed) 340:c869

    Article  Google Scholar 

  • Moher D, Hopewell S, Schulz KF, Montori V, Gotzsche PC, Devereaux PJ et al (2010b) CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. J Clin Epidemiol 63(8):e1–e37

    Article  Google Scholar 

  • Montgomery P, Grant S, Mayo-Wilson E, Macdonald G, Michie S, Hopewell S et al (2018) Reporting randomised trials of social and psychological interventions: the CONSORT-SPI 2018 extension. Trials 19(1):407

    Article  Google Scholar 

  • Pandis N, Chung B, Scherer RW, Elbourne D, Altman DG (2017) CONSORT 2010 statement: extension checklist for reporting within person randomised trials. BMJ (Clin Res Ed) 357:j2835

    Article  Google Scholar 

  • Piaggio G, Elbourne DR, Pocock SJ, Evans SJ, Altman DG (2012) Reporting of noninferiority and equivalence randomized trials: extension of the CONSORT 2010 statement. JAMA 308(24):2594–2604

    Article  Google Scholar 

  • Rennie D (1995) Reporting randomized controlled trials. An experiment and a call for responses from readers. JAMA 273(13):1054–1055

    Article  Google Scholar 

  • Savovic J, Jones HE, Altman DG, Harris RJ, Juni P, Pildal J et al (2012) Influence of reported study design characteristics on intervention effect estimates from randomized, controlled trials. Ann Intern Med 157(6):429–438

    Article  Google Scholar 

  • Schulz KM, Altman DG (2014) CONSORT [Chapter 7] published in guidelines for reporting health research: a users guide. Wiley Blackwell, Chichester

    Google Scholar 

  • Schulz KF, Altman DG, Moher D (2010a) CONSORT 2010 statement: updated guidelines for reporting parallel group randomized trials. Ann Intern Med 152(11):726–732

    Article  Google Scholar 

  • Schulz KF, Altman DG, Moher D (2010b) CONSORT 2010 statement: updated guidelines for reporting parallel group randomized trials. Open Med 4(1):e60–e68

    Google Scholar 

  • Schulz KF, Altman DG, Moher D (2010c) CONSORT 2010 statement: updated guidelines for reporting parallel group randomized trials. Obstet Gynecol 115(5):1063–1070

    Article  Google Scholar 

  • Schulz KF, Altman DG, Moher D (2010d) CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. PLoS Med 7(3):e1000251

    Article  Google Scholar 

  • Schulz KF, Altman DG, Moher D (2010e) CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. J Clin Epidemiol 63(8):834–840

    Article  Google Scholar 

  • Schulz KF, Altman DG, Moher D (2010f) CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. BMC Med 8:18

    Article  Google Scholar 

  • Schulz KF, Altman DG, Moher D (2010g) CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. Trials 11:32

    Article  Google Scholar 

  • Schulz KF, Altman DG, Moher D (2010h) CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. BMJ (Clin Res Ed) 340:c332

    Article  Google Scholar 

  • Shamseer L, Hopewell S, Altman DG, Moher D, Schulz KF (2016) Update on the endorsement of CONSORT by high impact factor journals: a survey of journal “Instructions to authors” in 2014. Trials 17(1):301

    Article  Google Scholar 

  • The Standards of Reporting Trials Group (1994) A proposal for structured reporting of randomized controlled trials. JAMA 272(24):1926–1931

    Article  Google Scholar 

  • Turner L, Shamseer L, Altman DG, Schulz KF, Moher D (2012) Does use of the CONSORT statement impact the completeness of reporting of randomised controlled trials published in medical journals? A Cochrane review. Syst Rev 1:60

    Article  Google Scholar 

  • Vohra S et al (2016) CONSORT extension for reporting N-of-1 trials (CENT) 2015 statement. BMJ (Clin Res Ed) 355:i5381

    Google Scholar 

  • Welch VA, Norheim OF, Jull J, Cookson R, Sommerfelt H, Tugwell P (2017) CONSORT-equity 2017 extension and elaboration for better reporting of health equity in randomised trials. BMJ (Clin Res Ed) 359:j5085

    Article  Google Scholar 

  • Wood L, Egger M, Gluud LL, Schulz KF, Juni P, Altman DG et al (2008) Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study. BMJ (Clin Res Ed) 336(7644):601–605

    Article  Google Scholar 

  • Working Group on Recommendations for Reporting of Clinical Trials in the Biomedical Literature (1994) Call for comments on a proposal to improve reporting of clinical trials in the biomedical literature. Ann Intern Med 121(11):894–895

    Article  Google Scholar 

  • Zwarenstein M, Treweek S, Gagnier JJ, Altman DG, Tunis S, Haynes B et al (2008) Improving the reporting of pragmatic trials: an extension of the CONSORT statement. BMJ (Clin Res Ed) 337:a2390

    Article  Google Scholar 

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Correspondence to Sally Hopewell .

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Chapter dedicated to Professor Doug Altman

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Hopewell, S., Boutron, I., Moher, D. (2020). CONSORT and Its Extensions for Reporting Clinical Trials. In: Piantadosi, S., Meinert, C. (eds) Principles and Practice of Clinical Trials. Springer, Cham. https://doi.org/10.1007/978-3-319-52677-5_188-1

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  • DOI: https://doi.org/10.1007/978-3-319-52677-5_188-1

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