March 19, 2019

Archives for February 1, 2015

World Health Organization’s advice based on weak evidence, Canadian-led study says

By: Tom Blackwell, National Post, Canada 01-Feb-2015 – In the confusing and fast-changing world of medicine, few voices carry as much weight as that of the World Health Organization.

But a new, Canadian-led analysis takes a poke at that reputation, concluding the UN agency often makes strong recommendations on how to treat or prevent illness based on weak evidence, potentially leading to patients getting less-than-optimum care.

The study concluded that 73 of 289 strong recommendations the agency issued over a recent five-year stretch — on topics ranging from maternal health to tuberculosis — were based on low-quality evidence and warranted only conditional advice.

“Historically, WHO recommendations have been extremely untrustworthy and not evidence-based,” said Dr. Gordon Guyatt, the study’s lead author. “Things have gotten better, but there is still a ways to go. … If the truth is that an intervention is ineffective or minimally effective, [patients and health workers] would want to know this.”

Historically, WHO recommendations have been extremely untrustworthy and not evidence-based

An official with the agency, however, says the problems are minor and that people have no reason to distrust its advice.

Dr. Guyatt and other critics suggest the issue extends beyond the Geneva-based WHO. Many other health organizations are likely still issuing advice based on flimsy science, the product of an unstructured process humorously dubbed GOBSAT — “good old boys sitting around the table,” he said.

Experts on guidelines-writing panels are often influenced by conflicts of interest, whether a bias toward their own prior research or financial ties to pharmaceutical companies and, until recently at least, the WHO was no exception, said Dr. Guyatt, an epidemiology professor at McMaster University in Hamilton, Ont.

“They would sit around and do whatever they wanted to do and direct the world, and be very pleased they directed the world.”

The goal is to move such panels toward more “evidence-based medicine,” a phrase Dr. Guyatt coined and a ubiquitous buzz-word in modern health-care. It involves putting more weight on better-quality science, with randomized-controlled trials being the pinnacle of evidence.

Susan Norris, a WHO official who helps oversee the writing of expert guidelines and commissioned the Canadian-led research, said it has identified areas where the process can be improved, and changes are being implemented. But she objected to Dr. Guyatt’s description of some of the recommendations as “inappropriate,” saying the agency remains trustworthy.

“Incorrect advice is not being communicated,” said Dr. Norris. “WHO’s process is state of the art, in terms of how we develop guidelines. … There’s always room for improvement, but the WHO has made tremendous improvements as the science has evolved.”

The agency’s guidelines panels also have daunting tasks, she added, trying to make research findings relevant for front-line health workers and patients in a host of disparate countries around the world.

They would sit around and do whatever they wanted to do and direct the world, and be very pleased they directed the world

Health organizations began producing guidelines about 30 years ago. The WHO regularly convenes leading international experts to hash out advice, which is especially important in poor- and middle-income countries with less-developed medical systems, said Dr. Guyatt.

After concerns were raised seven years ago, the agency implemented a system, called GRADE, for rating — and publicly disclosing — the quality of evidence behind the advice it issued. GRADE also permits strong recommendations with weak evidence in certain circumstances, such as when the proposed treatment could be life-saving and the side-effect risk is minimal.

The WHO is definitely making progress, said Dr. Guyatt.

The new study, however, found that of 289 strong recommendations in 33 guidelines it issued between 2007 and 2012, 73 were not only based on weak evidence, but could not be justified under any of the exceptions the system allowed.

One such recommendation, for instance, strongly advised using “uterine massage” to treat postpartum hemorrhage — heavy bleeding after giving birth. Because the advice is backed up by “very low-quality” evidence and could delay more effective treatment, it should have been just a conditional recommendation, the study concluded.

The guidelines issued by some medical-specialty groups have come under similar scrutiny — and even harsher criticism — in recent years.

A 2013 British Medical Journal article said the documents can play a valuable role, but that widespread financial conflicts of interests among the authors and sponsors of guidelines have turned many into “marketing tools of industry.”

“Biased guidelines can cause grave harms to patients, while creating a dilemma for doctors, who may face professional or legal consequences when they choose not to follow guidelines they distrust,” said the article.