04 Nov Non-Publication of Medical Research Remains an Issue
MedicalResearch.com: What are the main findings of the study?
Dr. Jones: We identified a group of 585 clinical trials with at least 500 participants which had been prospectively registered with ClinicalTrials.gov and completed prior to 2009. Following an extensive search of the medical literature, we were unable to identify published manuscripts for 171 (29%) of these studies. For these unpublished studies we also determined whether results were available in the ClinicalTrials.gov results database, and we found that 133 studies had no results available either in the published literature or on ClinicalTrials.gov.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Jones: Our observed rate of non-publication is similar to previously observed rates of non-publication among smaller trials. What was not previously known was whether non-publication is a significant problem among very large studies. Our results suggest that non-publication is common even among large trials. This is important to know because these trials often have the potential to significantly impact medical decision-making.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Jones: It is important to keep in mind that trial participants in general receive excellent care, and that multiple safeguards are used to ensure that trial participation is as safe as possible. Many trial participants, however, are motivated to enroll in studies because they believe that future patients are likely to benefit from the knowledge generated as a result of their participation. In order to maximize these benefits, trial data need to be published.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Jones: We believe that recent efforts to encourage trial registration and data transparency are important steps towards ensuring that trial data is routinely made publicly available. There clearly remains work to be done, however. We recognize the need to minimize the creation of additional expensive and burdensome barriers to the conduct of clinical trials, and additional study is needed to anticipate and limit the unintended consequences of future measures intended to improve transparency.
Non-publication of large randomized clinical trials: cross sectional analysis
Jones CW ,Handler L ,Crowell KE ,Keil LG ,Weaver MA ,Platts-Mills TF. Non-publication of large randomized clinical trials: cross sectional analysis. BMJ 2013;347:f6104