New study finds many concerns with clinical trials

Jun 21 2005

A new study led by OHRI Scientist and University of Ottawa Professor, Dr. Dean Fergusson, has looked at current practices in justifying the conduct of clinical trials and found many concerns. For starters, the report notes, some researchers don't even look at existing evidence, repeating trials that have already been conducted and scientifically validated. The study appears in Society for Clinical Trials.

"In some instances, a number of redundant trials have been conducted without sound scientific or ethical justification," concluded Dr. Fergusson. The article points to randomized control trials of aprotinin in cardiac surgery to reduce transfusion requirements as an example. Dr. Fergusson found 64 randomized, controlled trials of aprotinin between 1987 and 2002 - most of them investigating already determined conclusions. Dr. Fergusson further noted that trialists evaluating aprotinin were not adequately citing previous trials nor conducting systematic reviews to support the need for additional trials. The result was a number of unnecessary trials which included a large number of patients - rendering the use of placebo or no-treatment controls questionable.

To improve current practices, Dr. Fergusson suggests that investigators be required to conduct more organized reviews of evidence using well-established standards and scientific methods of systematic reviewing. Research ethics boards and journals would be tasked with determining the thoroughness of these efforts. The danger of repeating existing trials, Dr. Fergusson continues, is that you expose patients to known inferior treatments by assigning them to receive a placebo. Patients would be better served by trials that cover new products or study unknown, potential side effects said Dr. Fergusson, who was recently featured in the news for a study that looks at anti-depressants and increased risk of suicide. "To be ethical, clinical research must be valuable. In order to evaluate whether a trial will add to current knowledge, a systematic review of the literature is absolutely necessary," according to Dr. Fergusson.

But Dr. Fergusson is quick to point out that clinical trials, as a general principal, are essential and often, conducted quite well. "Randomized clinical trials remain the gold standard of assessing whether a therapy is effective or not," he reminds us. "As such, clinical trials have significantly influenced practice and improved the health of many lives. In order to continue to improve the well-being of patients, we must ensure that we are asking and answering scientifically and ethically defensible questions."

The onus also lies on the research ethics committees who approve these trials and the journals that publish them. Government funded organizations, such as the Canadian Institutes of Health Research, already require systematic reviews of existing trials.

"The article by Dean Fergusson and his colleagues in this issue of the journal is the most recent evidence of an ongoing scandal in which research funders, academia, researchers, research ethics committees and scientific journals are all complicit," notes Sir Iain Chalmers, a well respected and highly prolific researcher with the James Lind Alliance in Oxford, UK.

"This study demonstrates the need to review systematically previous studies when planning new studies to ensure that the research question has not already been answered," said Dr. Jeremy Grimshaw, Director of the Clinical Epidemiology Program at the OHRI. "Failure to do this risks exposing patients to proven ineffective treatments or denying patients proven effective treatments and poor use of scarce public research funding."

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