The World Health Organization's building in Geneva, Switzerland.

The World Health Organization's building in Geneva, Switzerland.

Yann (talk)/Wikimedia Commons

Withholding results from clinical trials is unethical, says WHO

The movement to ensure that clinical trial results don't end up in drawers has found an important global ally. Today, the World Health Organization (WHO) issued a call to make results from every clinical study publicly available within a year. Not doing so can harm patients and research subjects, waste time and money, and hold back medical science, WHO says.

“Failure to publicly disclose trial results engenders misinformation, leading to skewed priorities for both R&D and public health interventions,” said Marie-Paule Kieny, an assistant-director at WHO, in a press statement today. “It creates indirect costs for public and private entities, including patients themselves, who pay for suboptimal or harmful treatments.”

Clinical trials go unpublished for a variety of reasons. Sometimes a study's sponsor prefers not to call attention to unwelcome results; sometimes researchers have trouble getting a journal to print their findings—for instance if they show a treatment had no effect; and sometimes scientists never get around to writing a manuscript. But withholding results leads to "publication bias," which causes treatments to seem more or less effective than they really are, and it can put volunteers in future trials at risk unnecessarily.

In its statement, WHO says that from now on the main findings of every clinical study should be submitted to a peer-reviewed journal within 12 months after data collection ends and be published—in an open-access journal unless there is a specific reason why that's impossible—within 24 months. "Main findings" may sound rather limited, but actually includes everything from trial design and eligibility criteria to the outcomes, limitations, and interpretation of a study. WHO refers researchers who want a checklist of what needs to be in a paper to the so-called CONSORT statement.

In addition, WHO wants the "key outcomes"—a more limited data set including number of participants, key results, and adverse events—made available in a clinical trial registry such as within 12 months after a study is completed. WHO also calls on the publication of the results from older studies that have never seen the light of day.

"It's unethical to conduct clinical research without reporting the results," says Vasee Moorthy, an author of a paper about the new statement published in PLOS Medicine today. Europe and the United States have already made important regulatory strides to registering trials and making their outcomes public, Moorthy says; he hopes WHO's statement will stimulate countries elsewhere to do the same.

Ben Goldacre, a co-founder of the advocacy group AllTrials, praises WHO's "landmark position statement" in another paper in PLOS Medicine, but says it's not enough. To make sure that researchers follow WHO's advice and fulfill their reporting obligations, Goldacre recommends independently conducted audits. For every trial entered in a trial registry more than 12 months ago, auditors can simply check whether the results have been published and post their findings. That "would allow us to name and shame poor performers, and also to reward best practice," Goldacre writes.

The requirement to publish in an academic journal may prove a red herring, Goldacre says, as journal articles are sometimes incomplete, wrong, or full of spin, and publication can take a long time. Reporting results in a structured database like is speedier and often better, he argues.