Non-publication and Delayed Publication of Randomized Trials on Vaccines: Survey
Conclusions Most vaccine trials are published eventually or the results posted in ClinicalTrials.gov, but delays to publication of several years are common. Actions should focus on the timely dissemination of data from vaccine trials to the public.
BMJ 2014;348:g3058 doi: 10.1136/bmj.g3058 (Published 16 May 2014)
OPEN ACCESS
Lamberto Manzoli associate professor 1 2, Maria Elena Flacco resident physician 1 3, Maddalena D’Addario resident physician 4 5, Lorenzo Capasso PhD student 1 Corrado De Vito assistant professor 6, Carolina Marzuillo assistant professor 6, Paolo Villari professor 6, John P A Ioannidis professor 7 8 1Department of Medicine and Aging Sciences, University of Chieti, Via dei Vestini 5 66013 Chieti, Italy; 2CeSI Biotech, Via Colle dell’Ara, Chieti, Italy; 3Local Health Unit of Pescara, Italy; 4Division of Clinical Epidemiology and Biostatistics, Institute of Social and Preventive Medicine, University of Bern, Switzerland; 5Division of International and Environmental Health, Institute of Social and Preventive Medicine, University of Bern, Switzerland; 6Department of Public Health and Infectious Diseases, Sapienza University of Rome, Italy; 7Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA; 8Department of Health Research and Policy, Stanford University School of Medicine, Stanford, CA, USA
Abstract
Objective To evaluate the extent of non-publication or delayed publication of registered randomized trials on vaccines, and to investigate potential determinants of delay to publication.
Design Survey.
Data sources Trials registry websites, Scopus, PubMed, Google. Study selection Randomized controlled trials evaluating the safety or the efficacy or immunogenicity of human papillomavirus (HPV), pandemic A/H1N1 2009 influenza, and meningococcal, pneumococcal, and
rotavirus vaccines that were registered in ClinicalTrials.gov, Current Controlled Trials, WHO International Clinical Trials Registry Platform, Clinical Study Register, or Indian, Australian-New Zealand, and Chinese trial registries in 2006-12. Electronic databases were searched up to
February 2014 to identify published manuscripts containing trial results. These were reviewed and classified as positive, mixed, or negative. We also reviewed the results available in ClinicalTrials.gov. Main outcome measures Publication status of trial results and time from completion to publication in peer reviewed journals. Data synthesis Cox proportional hazards regression was used to evaluate potential predictors of publication delay.
Results We analysed 384 trials (85% sponsored by industry). Of 355 trials (404 758 participants) that were completed, 176 (n=151 379) had been published in peer reviewed journals. Another 42 trials (total sample 62 765) remained unpublished but reported results in ClinicalTrials.gov.
The proportion of trials published 12, 24, 36, and 48 months after completion was 12%, 29%, 53%, and 73%, respectively. Including results posted in ClinicalTrials.gov, 48 months after study completion results were available for 82% of the trials and 90% of the participants. Delay
to publication between non-industry and industry sponsored trials did not differ, but non-industry sponsored trials were 4.42-fold (P=0.008) more likely to report negative or mixed findings. Negative results were reported by only 2% of the published trials.
Conclusions Most vaccine trials are published eventually or the results posted in ClinicalTrials.gov, but delays to publication of several years are common. Actions should focus on the timely dissemination of data from vaccine trials to the public.
Five companies funded 85% (276 of 326) of the industry sponsored trials. For GlaxoSmithKline, N=140.
Thirty-two percent of non-industry funded studies reported negative or mixed results vs. 7% of industry funded studies.
"Long since unpublished trials
"Supplementary table 2 on bmj.com shows the main characteristics of the 24 trials that remained unpublished after six years from completion. Most of those (n=14/24)
tested meningococcal vaccines, only one was sponsored by not
for profit institutions, and only five reported results in ClinicalTrials.gov. The 19 trials with no results at all included 11 527 participants. Despite our attempts, none of the people or institutions that we tried to contact provided any additional information on these long since unpublished trials."
Posted by: Jeannette Bishop | May 30, 2014 at 03:23 PM
Aren't researchers that go for open access wonderful!
Posted by: Jenny | May 30, 2014 at 07:35 AM