The Quality of Registration of Clinical Trials

Abstract

BackgroundLack of transparency in clinical trial conduct, publication bias and selective reporting bias are still important problems in medical research. Through clinical trials registration, it should be possible to take steps towards resolving some of these problems. However, previous evaluations of registered records of clinical trials have shown that registered information is often incomplete and non-meaningful. If these studies are accurate, this negates the possible benefits of registration of clinical trials.Methods and FindingsA 5% sample of records of clinical trials that were registered between 17 June 2008 and 17 June 2009 was taken from the International Clinical Trials Registry Platform (ICTRP) database and assessed for the presence of contact information, the presence of intervention specifics in drug trials and the quality of primary and secondary outcome reporting. 731 records were included. More than half of the records were registered after recruitment of the first participant. The name of a contact person was available in 94.4% of records from non-industry funded trials and 53.7% of records from industry funded trials. Either an email address or a phone number was present in 76.5% of non-industry funded trial records and in 56.5% of industry funded trial records. Although a drug name or company serial number was almost always provided, other drug intervention specifics were often omitted from registration. Of 3643 reported outcomes, 34.9% were specific measures with a meaningful time frame.ConclusionsClinical trials registration has the potential to contribute substantially to improving clinical trial transparency and reducing publication bias and selective reporting. These potential benefits are currently undermined by deficiencies in the provision of information in key areas of registered records.

Supplemental Project to Assess the Transparency of Reporting Requirements: Omega-3 Fatty Acids and Cardiovascular Disease

“…Obtaining empirical data on studies of dietary supplements (e.g., fish oil) and interventions (e.g., increase of fish servings per week) in the context of a major clinical condition (e.g., cardiovascular disease [CVD]) adds to existing knowledge because the mechanisms through which information bias operates in this case may differ from studies of medications. The existing empirical research on information bias pertains almost exclusively to industry-sponsored drug, device, and biologic trials, [15][16][17] despite the fact that 42 percent (88023) of all studies registered in ClinicalTrials.gov are indexed as "observational" or "behavioral/other intervention studies". 18 Omega-3 fatty acids derive from both dietary supplements and consumption through a variety of plants and animal sources and these studies typically fall under these observational and other intervention studies.…”

Clinical trial metadata: defining and extracting metadata on the design, conduct, results and costs of 125 randomised clinical trials funded by the National Institute for Health Research Health Technology Assessment programme

“…14 Patient groups had demanded ready access to information about clinical research studies so that they might be more fully informed about a range of potential treatment options, particularly for very serious diseases. The law emphasised that the information in such a registry must be easily accessible and available to patients, the public, health-care providers and researchers in a form that can be readily understood.…”

Analysis of Pediatric Clinical Drug Trials for Neuropsychiatric Conditions

“…29 This trial registry contains both domestic and international clinical trials and is estimated to include records for as many as 89% of all registered trials. 30,31 Given frequent delays in publication and failure to publish trials, clinical trial registries are preferable to using published research to evaluate current and complete research activity. 32,33 Trial records were selected and downloaded on November 1, 2011, using the following inclusion criteria: the trial studied 1 of the 5 conditions of interest, the trial was a drug intervention study addressing the efficacy and/or safety of an agent (ie, pharmacokinetic/dynamic and dose-finding trials were excluded), and the start date was on or after January 1, 2006.…”

“…50,52 A limitation of our study is that the CinicalTrials.gov registry may not include all relevant neuropsychiatric trials; however, this is the most accessible and comprehensive registry for domestic clinical research. 30 We also could not verify the information provided by investigators in the trial record and encountered records with some missing data. For the drug data, we could not ensure that our sources provided the most recently approved drug labels, although 2 separate references were used and all searches were performed separately by 2 of the investigators (S.M.…”