Photo by Esther Dyson
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:"Table Normal";
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0in 5.4pt 0in 5.4pt;
mso-para-margin-top:0in;
mso-para-margin-right:0in;
mso-para-margin-bottom:10.0pt;
mso-para-margin-left:0in;
line-height:115%;
mso-pagination:widow-orphan;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-ascii-font-family:Calibri;
mso-ascii-theme-font:minor-latin;
mso-hansi-font-family:Calibri;
mso-hansi-theme-font:minor-latin;}
The reporting requirements developed to increase transparency in US medical research may lead to fewer positive trial outcomes, according to a study published in PLOS ONE.
Researchers analyzed data from large-budget trials funded by the National Heart, Lung and Blood Institute (NHLBI).
And they found evidence suggesting the reporting requirements may have contributed to a significant reduction in studies with positive findings.
The reporting standards were phased in around 2000. They require researchers conducting drug or dietary supplement trials using human subjects to identify
projected outcomes and register their trials on ClinicalTrials.gov before they begin to collect data.
When entering their trial into the database, researchers are required to state the specific outcome on which they will focus. In the past, a researcher might have published an aspect of a study that was successful, even if the study overall did not produce the expected results.
But the new requirements mean researchers are less likely to change their analysis plan to consider another outcome that may have shown a positive result, said Veronica L. Irvin, PhD, of Oregon State University in Corvallis.
Dr Irvin began working on this project with the study’s lead author, Robert M. Kaplan, PhD, of the Agency for Healthcare Research and Quality in Rockville,
Maryland, while the two worked together in the National Institutes of Health’s Office of Behavior and Social Science Research.
The pair reviewed all large-budget clinical trials evaluating drugs or dietary supplements for the treatment or prevention of cardiovascular disease that had received funding from the NHLBI between 1970 and 2012.
They chose large-budget, NHLBI-funded trials in part because outcomes from the trials were more likely to be published, even if they did not produce the expected result.
Fifty-five studies were included in the research. Thirty were published prior to the reporting changes in 2000 (1970 to 1999), and 25 were published after the changes (2000 to 2012).
Of the studies published after 2000, only 2 (8%) showed positive outcomes, while 17 (57%) of the studies published before 2000 showed positive results.
Drs Kaplan and Irvin acknowledged that factors other than the reporting requirements may be contributing to the decline in positive outcomes, but they were unable to identify other compelling explanations.
For example, one suggestion was that older trials were more likely to compare new treatments to placebos, while newer trials were more likely to compare new
treatments to established treatments.
But when Drs Kaplan and Irvin examined the data, they found that 60% of trials published before 2000 used placebo comparators and nearly the same amount, 64%, of trials published after 2000 used placebos.
The researchers noted that although this work focused on clinical trials related to cardiovascular health, it would be reasonable to see similar changes in results
across other disease types.
“We don’t know if this decrease in positive outcomes also affects drug trials for prevention and treatment of cancer, diabetes, or other diseases,” Dr Irvin said. “But it would not be surprising because they have the same reporting requirements.”
