Review Article| Volume 60, ISSUE 3, P241-249, March 2007

Reporting in randomized clinical trials improved after adoption of the CONSORT statement

  • Robert L. Kane
    Corresponding author. University of Minnesota School of Public Health, D351 Mayo (MMC 197), 420 Delaware Street SE, Minneapolis, MN 55455, USA. Tel.: 612-624-1185; fax: 612-624-8448.
    University of Minnesota Clinical Outcomes Research Center, Minneapolis, MN, USA

    University of Minnesota School of Public Health, Division of Health Policy and Management, Minneapolis, MN, USA
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  • Jye Wang
    University of Minnesota School of Public Health, Division of Health Policy and Management, Minneapolis, MN, USA
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  • Judith Garrard
    University of Minnesota School of Public Health, Division of Health Policy and Management, Minneapolis, MN, USA
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      To examine the extent to which the Consolidated Standards of Reporting Trials (CONSORT) reporting guidelines improved clinical trials reporting and subject attrition, which may undermine the credibility of published randomized clinical trials (RCTs).

      Study Design and Setting

      Published RCTs reported in two major medical journals before and after the CONSORT guidelines were systematically reviewed; one used the CONSORT statement (JAMA) and one did not (NEJM).


      The quality of RCT reporting improved for both journals, but JAMA showed more significant and consistent improvements in all aspects of RCT reporting. Subject attrition was better accounted for after the publication of CONSORT, although the attrition rates for various reasons actually increased. Attrition due to unknown reasons, as a percentage of total attrition, declined dramatically, from 68.7% pre-CONSORT to 13.0% post-CONSORT.


      Attrition of study subjects remains a serious problem in RCTs. Bias from selective attrition can undermine the presumptive scientific advantage of RCTs. The CONSORT guidelines improved RCT reporting when they were implemented but did not substantially improve reported attrition rates.


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