Clinical trial registry

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Randomized clinical trials are the primary method of testing the safety and efficacy of new medical treatments. Thus they are the foundation of evidence-based medicine, and they are critical in the creation of clinical guidelines. There is concern in the medical community about publication bias of clinical trial results. The results of many trials are never published, and positive results are more likely to be published than negative results. The American Medical Association has written

“Unfortunately, selective reporting of trials does occur, and it distorts the body of evidence available for clinical decision-making. … The case against selective reporting is particularly compelling for research that tests interventions that could enter mainstream clinical practice. Rather than a single trial, it is usually a body of evidence, consisting of many studies, that changes medical practice. When research sponsors or investigators conceal the presence of selected trials, these studies cannot influence the thinking of patients, clinicians, other researchers, and experts who write practice guidelines or decide on insurance-coverage policy.” [1]

In an effort to eliminate publication bias, the American Medical Association advocates mandatory registration of all clinical trials in public trial registries. To encourage this practice, the International Committee of Medical Journal Editors (ICMJE) requires researchers to register clinical trials in a clinical trial registry, such as, as a condition of publication in their member journals. The ICMJE requires that general information about the trial, such as its hypothesis, outcome measures, schedule, target number of subjects, and funding source be entered into a registry. However, the ICMJE does not currently require that the results of clinical trials be published in a registry. [1]

Some in the medical community want to take the registration of clinical trials one step further – they want the results of clinical trials to be publically available in registries. They feel this step will “improve research transparency and will ultimately strengthen the validity and value of the scientific evidence base.” [2] Thus, there are efforts underway to store clinical trial results in registries, such as the WHO International Clinical Trials Registry. [2] There are also initiatives to store clinical trial results in registries in computer-understandable formats to allow easy querying about trials or results and to allow data mining.

One such initiative is the Global Trial Bank of the American Medical Informatics Association (AMIA). AMIA’s goal is to create “the world’s peer-reviewed repository of protocols and results from clinical trials of all types.” AMIA hopes to store results from trials conducted by universities, government agencies, and the pharmaceutical/biotechnology industry. Most importantly, the results in the Global Trial Bank will contain data coded using SNOMED-CT so that “decision support systems can directly access the knowledge over the Internet.” [3]

Another initiative is the Trial Bank Project created by Ida Sim of the University of California San Francisco. Dr. Sim stores the “design, execution and result information from randomized clinical trials (RCTs) directly into computer-understandable ‘trial banks’". The clinical trials data is organized into a hierarchical data schema. The schema is available for viewing at . In addition, the public can browse the design and results data for trials in the Trial Bank Project at Dr. Sim is collaborating with JAMA and the Annals of Internal Medicine journals to store the randomized clinical trial results that they publish. [4]


  1. 1.0 1.1 DeAngelis, C., Drazen, J., et al. (2004). Clinical Trial Registration – A Statement from the International Committee of Medical Journal Editors. Journal of the American Medical Association. September 15, 2004, Vol. 292, No. 11.
  2. 2.0 2.1 World Health Organization (2007). International Clinical Trials Registry Platform.
  3. American Medical Informatics Association (2006). Global Trial Bank.
  4. Sim, I. (2007). The Trial Bank Project