Senior scientists have reported flaws in an influential WHO-commissioned study into the risks of coronavirus infection and say it should not be used as evidence for relaxing the UK’s 2m physical distancing rule.
Critics of the distancing advice, which states that people should keep at least 2m apart, believe it is too cautious.
They seized on the research commissioned by the WHO, which suggested a reduction from 2m to 1m would raise infection risk only marginally, from 1.3 percent to 2.6 percent.
Photo: Bloomberg
However, scientists who delved into the work found mistakes they believe undermine the findings to the point they cannot be relied upon when scientists and ministers are forming judgements about what constitutes safe physical distancing.
“The analysis of infection risk at 1 meter versus 2 meter should be treated with great caution,” said David Spiegelhalter, a statistician at Cambridge University, who has participated in the government’s Scientific Advisory Group for Emergencies. “I’m very suspicious of it.”
Kevin McConway, an applied statistician at the Open University, went further and called the analysis inappropriate.
He said the work “should not be used in arguments about how much greater the infection risk is at 1-meter minimum distance as opposed to 2 meters.”
The study, published in the Lancet, is the latest to come under fire from experts who fear that in the midst of the pandemic some research papers are being written, reviewed and published too fast for sufficient quality checks to be performed.
Led by researchers at McMaster University in Ontario, Canada, the report pooled data from previously published studies to estimate the risk of becoming infected with coronavirus at different distances. It also considered how masks and eye protection might help prevent the spread of disease.
However, in the analysis the authors assume the proportional impact on risk of moving from 2m to 1m is the same as moving from 1m to zero.
“They are forcing the proportional fit to be the same,” Spiegelhalter told the Guardian.
McConway believes there is a more fundamental problem in the way the risks of infection at different distances are compared in the study.
“The method of comparing the different distances in the paper is inappropriate for telling you exactly how the risk at 2 meter minimum distance compares to a 1 meter minimum distance. It does not support, and should not be used in, arguments about how much greater the risk is with a 1-meter limit versus a 2-metre limit,” he said.
Ben Cowling at the WHO Collaborating Centre for Infectious Disease Epidemiology and Control at the University of Hong Kong flagged further issues.
He tweeted that he was “not taking the whole paper very seriously,” because it looked only at distance and not how long a person was exposed. He believes peer review by the Lancet and the WHO should have spotted the problems.
“I think they did it in such a rush — the authors, possibly the WHO, and the Lancet peer reviewers — that important things were missed,” he said.
“Everyone believes that the risk of infection at 1-meter is higher than at 2-meter and we need to know how much higher because there’s a trade-off between the increased risk and the gains from moving to 1-meter. But if you don’t know how the risks at 1 meter and 2 meters compare, how do you know how to trade it off? It’s finger in the air stuff,” McConway said.
In a statement, the WHO said it recommends keeping a distance of 1m or more.
“The evidence used to inform this guidance was based on a systematic review of all available, relevant observational studies concerning protective measures to prevent transmission of the coronaviruses that cause SARS, MERS and COVID-19. After checking for relevance, 44 comparative studies done in healthcare and non-healthcare settings were included,” it said. “The findings of this systematic review and meta-analysis support physical distancing of 1 meter or more, which is in line with the existing WHO recommendation.”
CONFRONTATION: The water cannon attack was the second this month on the Philippine supply boat ‘Unaizah May 4,’ after an incident on March 5 The China Coast Guard yesterday morning blocked a Philippine supply vessel and damaged it with water cannons near a reef off the Southeast Asian country, the Philippines said. The Philippine military released video of what it said was a nearly hour-long attack off the Second Thomas Shoal (Renai Shoal, 仁愛暗沙) in the contested South China Sea, where Chinese ships have unleashed water cannons and collided with Philippine vessels in similar standoffs in the past few months. The China Coast Guard and other vessels “once again harassed, blocked, deployed water cannons, and executed dangerous maneuvers” against a routine rotation and resupply mission to
GLOBAL COMBAT AIR PROGRAM: The potential purchasers would be limited to the 15 nations with which Tokyo has signed defense partnership and equipment transfer deals Japan’s Cabinet yesterday approved a plan to sell future next-generation fighter jets that it is developing with the UK and Italy to other nations, in the latest move away from the country’s post-World War II pacifist principles. The contentious decision to allow international arms sales is expected to help secure Japan’s role in the joint fighter jet project, and is part of a move to build up the Japanese arms industry and bolster its role in global security. The Cabinet also endorsed a revision to Japan’s arms equipment and technology transfer guidelines to allow coproduced lethal weapons to be sold to nations
‘POLITICAL EARTHQUAKE’: Leo Varadkar said he was ‘no longer the best person’ to lead the nation and was stepping down for political, as well as personal, reasons Leo Varadkar on Wednesday announced that he was stepping down as Ireland’s prime minister and leader of the Fine Gael party in the governing coalition, citing “personal and political” reasons. Pundits called the surprise move, just 10 weeks before Ireland holds European Parliament and local elections, a “political earthquake.” A general election has to be held within a year. Irish Deputy Prime Minister Micheal Martin, leader of Fianna Fail, the main coalition partner, said Varadkar’s announcement was “unexpected,” but added that he expected the government to run its full term. An emotional Varadkar, who is in his second stint as prime minister and at
Thousands of devotees, some in a state of trance, gathered at a Buddhist temple on the outskirts of Bangkok renowned for sacred tattoos known as Sak Yant, paying their respects to a revered monk who mastered the practice and seeking purification. The gathering at Wat Bang Phra Buddhist temple is part of a Thai Wai Khru ritual in which devotees pay homage to Luang Phor Pern, the temple’s formal abbot, who died in 2002. He had a reputation for refining and popularizing the temple’s Sak Yant tattoo style. The idea that tattoos confer magical powers has existed in many parts of Asia