Article type
Year
Abstract
Background: The registration of clinical trials is an ethical and scientific imperative. It assures accountability for the conduct of ethical research and reduces duplication and biased reporting. The World Health Organization and the International Committee of Medical Journal Editors (ICMJE) have introduced mandatory trial registration policies since 2005 but few countries have supported these efforts with similar legislation. To date, it is unclear how many unregistered randomized controlled trials (RCTs) are conducted and subsequently published by scientific journals.
Objectives: To determine the frequency of reporting of RCT registration by country and by ICMJE member status, without restriction by journal, disease or specialty.
Methods: We identified and reviewed all primary reports of RCTs published in December 2012 and indexed in PubMed by 17 November 2013. There were no language restrictions. Reviews of abstracts, full text and data extraction were performed in duplicate. 62 non-English articles were reviewed by the same person on two occasions, several weeks apart. Country specific data were analyzed for locations wherein >40 RCTs were conducted. Registration rates in ICMJE and non-ICMJE journals were compared by a chi-squared test.
Results: 4190 abstracts were reviewed, 1370 primary RCTs were identified and 560 (40.9%) RCTs were reported as registered in the final publication. Among countries with >40 RCTs (figure 1), trial registration was highest in the United States at 53.2% and lowest in China at 18.6%. ICMJE journals published 297 (21.7%) RCTs and the proportion of registered trials was significantly higher than in non-ICMJE journals (185 (62.3%) vs. 375 (35.0%), p<0.001). 153,613 participants (34.2%) were randomized for RCTs that were not reported as registered.
Conclusions: Irrespective of medical specialty, journal or disease, reporting of RCT registration remains problematic. The majority of RCTs are published in non-ICMJE member journals, limiting the broad applicability of ICMJE policy. Country specific legislation and efforts by national research authorities are needed to achieve universal reporting of trial registration.
Objectives: To determine the frequency of reporting of RCT registration by country and by ICMJE member status, without restriction by journal, disease or specialty.
Methods: We identified and reviewed all primary reports of RCTs published in December 2012 and indexed in PubMed by 17 November 2013. There were no language restrictions. Reviews of abstracts, full text and data extraction were performed in duplicate. 62 non-English articles were reviewed by the same person on two occasions, several weeks apart. Country specific data were analyzed for locations wherein >40 RCTs were conducted. Registration rates in ICMJE and non-ICMJE journals were compared by a chi-squared test.
Results: 4190 abstracts were reviewed, 1370 primary RCTs were identified and 560 (40.9%) RCTs were reported as registered in the final publication. Among countries with >40 RCTs (figure 1), trial registration was highest in the United States at 53.2% and lowest in China at 18.6%. ICMJE journals published 297 (21.7%) RCTs and the proportion of registered trials was significantly higher than in non-ICMJE journals (185 (62.3%) vs. 375 (35.0%), p<0.001). 153,613 participants (34.2%) were randomized for RCTs that were not reported as registered.
Conclusions: Irrespective of medical specialty, journal or disease, reporting of RCT registration remains problematic. The majority of RCTs are published in non-ICMJE member journals, limiting the broad applicability of ICMJE policy. Country specific legislation and efforts by national research authorities are needed to achieve universal reporting of trial registration.