TY - JOUR
T1 - Extent of non-publication in cohorts of studies approved by research ethics committees or included in trial registries
AU - Schmucker, Christine
AU - Schell, Lisa K.
AU - Portalupi, Susan
AU - Oeller, Patrick
AU - Cabrera, Laura
AU - Bassler, Dirk
AU - Schwarzer, Guido
AU - Scherer, Roberta W.
AU - Antes, Gerd
AU - Von Elm, Erik
AU - Meerpohl, Joerg J.
AU - Bertele, Vittorio
AU - Bonfill, Xavier
AU - Bouesseau, Marie Charlotte
AU - Boutron, Isabelle
AU - Gallus, Silvano
AU - Garattini, Silvio
AU - Ghassan, Karam
AU - La Vecchia, Carlo
AU - Lang, Britta
AU - Littmann, Jasper
AU - Kleijnen, Jos
AU - Kulig, Michael
AU - Malicki, Mario
AU - Marusic, Ana
AU - Mueller, Katharina Felicitas
AU - Pardo, Hector
AU - Perleth, Matthias
AU - Ravaud, Philippe
AU - Reis, Andreas
AU - Strech, Daniel
AU - Trinquart, Ludovic
AU - Tia, Gerard Urrú
AU - Wager, Elizabeth
AU - Wieland, Alexandra
AU - Wolff., Robert
N1 - Funding Information:
In response to these concerns, the OPEN Project (To Overcome failure to Publish nEgative fiNdings; www.open-project.eu ) was developed with the goal of elucidating the scope of non-publication of studies through a series of systematic reviews and to develop recommendations. , – The OPEN Project was funded by the European Commission and conducted by an international working group of methodologists and other experts (see .). Besides evaluating the extent of non-publication of studies, OPEN examined current publication practices of key groups in the field of biomedical research (e.g., funding agencies, pharmaceutical industry, research ethics committees [RECs], trial registries, biomedical journals and regulatory agencies) through surveys and analysis of current policies and guidelines.
Publisher Copyright:
© 2014 Schmucker et al.
PY - 2014/12/23
Y1 - 2014/12/23
N2 - Background: The synthesis of published research in systematic reviews is essential when providing evidence to inform clinical and health policy decisionmaking. However, the validity of systematic reviews is threatened if journal publications represent a biased selection of all studies that have been conducted (dissemination bias). To investigate the extent of dissemination bias we conducted a systematic review that determined the proportion of studies published as peerreviewed journal articles and investigated factors associated with full publication in cohorts of studies (i) approved by research ethics committees (RECs) or (ii) included in trial registries.Methods and Findings: Four bibliographic databases were searched for methodological research projects (MRPs) without limitations for publication year, language or study location. The searches were supplemented by handsearching the references of included MRPs. We estimated the proportion of studies published using prediction intervals (PI) and a random effects meta-analysis. Pooled odds ratios (OR) were used to express associations between study characteristics and journal publication. Seventeen MRPs (23 publications) evaluated cohorts of studies approved by RECs; the proportion of published studies had a PI between 22% and 72% and the weighted pooled proportion when combining estimates would be 46.2% (95% CI 40.2%-52.4%, I2594.4%). Twenty-two MRPs (22 publications) evaluated cohorts of studies included in trial registries; the PI of the proportion published ranged from 13% to 90% and the weighted pooled proportion would be 54.2% (95% CI 42.0%-65.9%, I2598.9%). REC-approved studies with statistically significant results (compared with those without statistically significant results) were more likely to be published (pooled OR 2.8; 95% CI 2.2-3.5). Phase-III trials were also more likely to be published than phase II trials (pooled OR 2.0; 95% CI 1.6- 2.5). The probability of publication within two years after study completion ranged from 7% to 30%.Conclusions: A substantial part of the studies approved by RECs or included in trial registries remains unpublished. Due to the large heterogeneity a prediction of the publication probability for a future study is very uncertain. Non-publication of research is not a random process, e.g., it is associated with the direction of study findings. Our findings suggest that the dissemination of research findings is biased.
AB - Background: The synthesis of published research in systematic reviews is essential when providing evidence to inform clinical and health policy decisionmaking. However, the validity of systematic reviews is threatened if journal publications represent a biased selection of all studies that have been conducted (dissemination bias). To investigate the extent of dissemination bias we conducted a systematic review that determined the proportion of studies published as peerreviewed journal articles and investigated factors associated with full publication in cohorts of studies (i) approved by research ethics committees (RECs) or (ii) included in trial registries.Methods and Findings: Four bibliographic databases were searched for methodological research projects (MRPs) without limitations for publication year, language or study location. The searches were supplemented by handsearching the references of included MRPs. We estimated the proportion of studies published using prediction intervals (PI) and a random effects meta-analysis. Pooled odds ratios (OR) were used to express associations between study characteristics and journal publication. Seventeen MRPs (23 publications) evaluated cohorts of studies approved by RECs; the proportion of published studies had a PI between 22% and 72% and the weighted pooled proportion when combining estimates would be 46.2% (95% CI 40.2%-52.4%, I2594.4%). Twenty-two MRPs (22 publications) evaluated cohorts of studies included in trial registries; the PI of the proportion published ranged from 13% to 90% and the weighted pooled proportion would be 54.2% (95% CI 42.0%-65.9%, I2598.9%). REC-approved studies with statistically significant results (compared with those without statistically significant results) were more likely to be published (pooled OR 2.8; 95% CI 2.2-3.5). Phase-III trials were also more likely to be published than phase II trials (pooled OR 2.0; 95% CI 1.6- 2.5). The probability of publication within two years after study completion ranged from 7% to 30%.Conclusions: A substantial part of the studies approved by RECs or included in trial registries remains unpublished. Due to the large heterogeneity a prediction of the publication probability for a future study is very uncertain. Non-publication of research is not a random process, e.g., it is associated with the direction of study findings. Our findings suggest that the dissemination of research findings is biased.
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U2 - 10.1371/journal.pone.0114023
DO - 10.1371/journal.pone.0114023
M3 - Article
C2 - 25536072
AN - SCOPUS:84919808207
SN - 1932-6203
VL - 9
JO - PloS one
JF - PloS one
IS - 12
M1 - e114023
ER -