Results of Many Clinical Trials Take Years to Publish
THURSDAY, Feb. 18, 2016 (HealthDay News) -- Medical researchers conducting the majority of clinical trials in the United States fail to report their results in a timely manner, new research reveals.
Less than one-third of clinical studies performed at major academic medical institutions are published within two years of completion -- a lapse that deprives the scientific community of time-sensitive, valuable information, investigators said.
"The reasons are unclear, but the consequences are profound," said study co-author Dr. Harlan Krumholz, a professor of medicine at the Yale School of Medicine in New Haven, Conn.
"By not reporting results, the scientific findings literature is harmed because it is incomplete," Krumholz said. "Patients are harmed because their doctors have access to only part of the evidence that has been generated, and the people who agreed to be in the studies are dishonored."
Randomized clinical trials are the best way to assess the effectiveness and safety of medical drugs and devices, the study authors explained. However, "the culture of medical research has evolved to the point where it is common practice not to report or publish studies, leaving it to the discretion of the researchers," Krumholz said.
To evaluate human-study reporting practices at leading academic medical institutions, the investigators examined information from the ClinicalTrials.gov database in 2013. This database is the largest such registry in the United States.
The researchers focused on U.S. studies with registrations indicating that all data-collecting efforts were scheduled to conclude at some point between 2007 and 2010.
Krumholz and colleagues identified more than 4,300 completed studies, conducted by 51 well-known academic institutions.
"We found that none of the prominent academic centers were doing well. All had many studies that were either not reported or published, or certainly not done within even two years of completing the studies," Krumholz said.
Even when the government mandates the results be made public, they often go unreported, he added.
Overall, only 29 percent of the studies were published within two years of completion, the investigators found. And the findings of only 13 percent were reported on the ClinicalTrials.gov website in the same time frame.
Eventually, two-thirds of the studies were published, though often long after the two-year wrap-up mark, according to the report in the Feb. 17 online edition of the BMJ.
Publication patterns varied widely, Krumholz and colleagues found. While some major academic medical centers published the findings of roughly 40 percent of their fully completed studies within 24 months, others reported less than 11 percent of their findings in that time frame.
With regards to the ClinicalTrials.gov website, reporting patterns ranged from less than 2 percent to about 40 percent. Similar variations were seen in reporting results from completed stages of ongoing clinical trials.
Unfortunately, "there is little consequence to not publishing," Krumholz said, calling this an increasingly common and "perplexing" practice.
"We have tried to understand what accounts for the lack of publication," he said. "Certainly, undesirable results might be part of the issue. The bottom line, though, is that it is an abrogation of our responsibility as scientists and health care professionals," Krumholz added.
Another study published last March in the New England Journal of Medicine found that only about one out of 10 clinical trials met federal requirements to report results on ClinicalTrials.gov within one year of the study's completion.
In 2000, Congress authorized the creation of ClinicalTrials.gov to publicly report information about clinical trials. Later, a new law expanded the website's mandate, requiring sponsors of most trials to report basic summary results so Americans could have access to the data, according to background notes in the NEJM study.
"There's been a lot of prior concern that industry often withheld evidence that came to light later about their medical products, and that medical journals were selectively reporting the positive results from trials," Dr. Monique Anderson of Duke University, an author of the 2015 study, said at the time.
Jeff Francer, vice president of law for the Pharmaceutical Research and Manufacturers of America, a Washington, D.C.-based trade group, said that "biopharmaceutical companies remain committed to enhancing public health through responsible clinical trial data sharing."
Francer said his organization and its European counterpart -- the European Federation of Pharmaceutical Industries and Associations -- abide by a set of principles detailing their trial-data sharing goals.
Under these principles, he said, "member companies have committed to enhance clinical trial-data sharing with qualified researchers, share results with the patients who participate in clinical trials, enhance public access to clinical study information, and reaffirm their commitment to publish medically significant clinical trial results."