Clinical trials are necessary to help identify safe and effective methods for preventing, diagnosing, and treating diseases. However, a systematic review published in the journal Med finds that clinical trial protocols often do not reference accessible, relevant trials and do not document systematic searches for relevant clinical trials. Subsequently, ethics review committees receive an incomplete picture of the research landscape if they review the protocols.

“Numerous studies suggest that some clinical trials are pursued despite their clinical hypotheses having been resolved prior to study launch,” said the authors. “Failure to provide a complete and impartial account of prior and ongoing research in study protocols may enable clinical research that fails to inform clinical practice.”

Using the registry ClinicalTrials.gov, the researchers evaluated 101 randomly chosen clinical trials. They found that of the protocols evaluated, 73 had at least one identified citable trial, yet none contained statements suggesting a systematic search for relevant clinical evidence. When they looked at industry-sponsored trial protocols with at least one identified citable trial, they found that 7 of 23 (30.4%) did not cite any published clinical trials and 10 of 33 (30.3%) did not cite any ongoing relevant trials. In comparison 5 of 28 (17.9%) non-industry-sponsored trial protocols with at least one identified citable trial did not cite any published clinical trials and 14 of 19 (73.7%) did not cite any ongoing trials.

The complete study and data can be read here.

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