Methodology – Page 11 – artdiamondblog.com

“People Are Now Coming to Their Own Conclusions About Covid”

(p. 3) Lauren Terry, 23, thought she would know what to do if she contracted Covid-19. After all, she manages a lab in Tucson that processes Covid tests.

But when she developed symptoms on Christmas Eve, she quickly realized she had no inside information.

“I first tried to take whatever rapid tests I could get my hands on,” Ms. Terry said. “I bought some over the counter. I got a free kit from my county library. A friend gave me a box. I think I tried five different brands.” When they all turned up negative, she took a P.C.R. test, but that too, was negative.

With clear symptoms, she didn’t believe the results. So she turned to Twitter. “I was searching for the Omicron rapid test efficacy and trying to figure out what brand works on this variant and what doesn’t and how long they take to produce results,” she said. (The Food and Drug Administration has said that rapid antigen tests may be less sensitive to the Omicron variant but has not identified any specific tests that outright fail to detect it.) “I started seeing people on Twitter say they were having symptoms and only testing positive days later. I decided not to see anybody for the holidays when I read that.”

She kept testing, and a few days after Christmas she received the result she had expected all along.

Though it’s been almost two years since the onset of the pandemic, this phase can feel more confusing than its start, in March 2020. Even P.C.R. tests, the gold standard, don’t always detect every case, especially early in the course of infection, and there is some doubt among scientists about whether rapid antigen tests perform as well with Omicron. And, the need for a 10-day isolation period was thrown into question after the Centers for Disease Control and Prevention announced that some people could leave their homes after only five days.

“The information is more confusing because the threat itself is more confusing,” said David Abramson, who directs the Center for Public Health Disaster Science at the N.Y.U. School of Global Public Health. “We used to know there was a hurricane coming at us from 50 miles away. Now we have this storm that is not well defined that could maybe create flood or some wind damage, but there are so many uncertainties, and we just aren’t sure.”

Many people are now coming to their own conclusions about Covid and how they should behave. After not contracting the virus after multiple exposures, they may conclude they can take more risks. Or if they have Covid they may choose to stay in isolation longer than the C.D.C. recommends.

And they aren’t necessarily embracing conspiracy theories. People are forming opinions after reading mainstream news articles and tweets from epidemiologists; they are looking at real-life experiences of people in their networks.

For the full story, see:

Alyson Krueger. “Covid Experts, the Self-Made Kind.” The New York Times, SundayStyles Section (Sunday, January 23, 2022): 3.

(Note: the online version of the story has the date January 21, 2022, and has the title “So You Think You’re a Covid Expert (but Are You?).”)

Expert Medical Advice Often Flip-Flops

(p. D6) A History of Medical Flip-Flops

Shifting medical advice is surprisingly common, and it tends to fall into three categories: emerging guidance, replacement advice and reversals.

Emerging guidance comes during times of crisis — like pandemics — and is destined to change quickly. In the past several months, guidance about the best way to treat Covid patients, masks to prevent transmission and the limits of vaccine protection have all shifted as knowledge of the coronavirus and its variants has evolved.

Sometimes it’s hard to tell the difference between replacement advice, which is issued when research improves on advice that came before it, and a full reversal, which comes about because a common medical practice got ahead of the science and never actually worked or even caused harm. Here are some examples of true medical flip-flops in recent years.

MENOPAUSE HORMONES TO PROTECT THE HEART: In 2002, decades of advice about the heart benefits of menopause hormones seemed to change overnight when a major study called the Women’s Health Initiative was halted after researchers detected more heart attacks in the women taking hormones. In hindsight, doctors had misinterpreted data from observational research. The current advice: Hormones can relieve menopause symptoms but shouldn’t be used for chronic disease prevention.

VIOXX AS A LOWER-RISK ARTHRITIS TREATMENT: In 1999, the Food and Drug Administration approved Vioxx as a breakthrough pain reliever because it lowered the risk of gastrointestinal problems. But by 2004, Merck had withdrawn the drug because studies showed it significantly raised the risk of heart attack.

ARTHROSCOPIC SURGERY ON AGING KNEES: For years, the partial removal of torn meniscus tissue was the most common orthopedic procedure in the United States, with about 700,000 performed a year. In 2013, a researcher in Finland compared the operation to a “sham” procedure and found there was no benefit. Most doctors now recommend physical therapy instead.

VITAMIN MEGADOSES TO LOWER CANCER AND HEART RISK: For years, doctors believed various vitamins could lower risk for cancer and heart disease, but a number of studies showed just the opposite. A study of beta carotene and vitamin A found that the supplements actually increased the risk of lung cancer in male smokers. A study of vitamin E and selenium, thought to protect against prostate cancer, increased risk for the disease.

STENTS FOR STABLE HEART DISEASE: Doctors used to insert stents — tiny wire mesh tubes that prop open arteries — in millions of otherwise stable patients with heart disease. A study found that the surgical procedure was no better than drug therapy for preventing heart attacks.

Dr. Vinay Prasad, associate professor at the University of California San Francisco, and Dr. Adam S. Cifu, a professor of medicine at the University of Chicago Department of Medicine, coined the term “medical reversal” and concluded that about 40 percent of common medical practices that they reviewed turned out to be useless or harmful. In their book, “Ending Medical Reversal: Improving Outcomes, Saving Lives,” they noted that most of these failed treatments were initially embraced because they were based on logical reasoning.

“The thing that’s often behind reversal: All of these things have a good story, they have good pathophysiological rationale,” Dr. Cifu said. “They should work. But things only work if they’ve been shown in people to work, and people are so complicated.”

For the full story, see:

Tara Parker-Pope. “Shifting Medical Advice Is a Feature, Not a Bug.” The New York Times (Tuesday, November 2, 2021): D6.

(Note: the online version of the story was updated Oct. 24, 2021, and has the title “Is the New Aspirin Advice a Medical Flip-Flop, or Just Science?” The paragraphs on menopause hormones to protect the heart and on vitamin megadoses to lower cancer and heart risk appear in the online version, but not in the print version.)

The book co-authored by Prasad and mentioned above is:

Prasad, Vinayak K., and Adam S. Cifu. Ending Medical Reversal: Improving Outcomes, Saving Lives. Baltimore: Johns Hopkins University Press, 2015.

The “Gold Standard” of Randomized Clinical Trials “Has Its Own Issues”

(p. R2) . . ., closely held Epic Systems Corp., maker of one of the most widely used electronic health record systems, searched a segment of its database in the spring of 2020 to find that routine breast, colon and cervical cancer screenings in the U.S. had each dropped by more than 85% during the first weeks of the Covid-19 pandemic. The report helped spur efforts to persuade people to make up for missed screenings.

But researchers have a much more ambitious vision for this data: to help guide how doctors treat individual patients in real time.

“The evidence from real-world data is a different and exciting new path,” says Jackie Gerhart, a physician who works with the informatics team at Epic. “You can get a lot of outcomes information from medical records that can help change care for individual patients.”

. . .

To be sure, patient records are observational, and thus subject to confounders and other shortcomings that can undercut their reliability in pointing to treatment options.

But the gold standard has its own issues. Randomized clinical trials, which control for differences in patient health status and other variables, are the preferred evidence to inform patient care. Yet such trials generally exclude an especially common group of patients—those with multiple ailments. Moreover, the elderly, children, women, minority groups and people who live far from medical research centers have long been underrepresented in such studies.

As a result, the highest-quality evidence that medicine produces doesn’t apply to most patients doctors see in daily practice. “There are so many clinical situations where the evidence that is needed does not exist,” says Nigam Shah, professor of medicine and biomedical data science at Stanford University Medical School.

Researchers have believed for at least a half-century that data in patient medical records could help fill the gaps.

. . .

The struggles of International Business Machines Corp.’s Watson raises [a] . . . yellow flag. It had ambitions to develop a tool for cancer doctors that would mine patient health records and thousands of pages of research from the peer-reviewed medical literature for treatment advice. But it hit walls, including accuracy and the complexity of combining data from electronic health records, billing claims and published research to provide a cohesive product. Doctors who used the service rarely changed treatment plans. IBM says it discontinued Watson for Oncology at the end of 2020.

For the full story, see:

Ron Winslow. “Mining the Gold in Patient Records.” The Wall Street Journal (Thursday, December 9, 2021): R2.

(Note: ellipses, and bracketed word, added.)

(Note: the online version of the story has the date December 3, 2021, and has the title “Medical Records Data Offers Doctors Hope of Better Patient Care.” In a couple of passages there are a few extra words in the online version, which is the version quoted above.)

IBM Sells Failed Watson Artificial Intelligence Health Unit

(p. B3) International Business Machines Corp. agreed to sell the data and analytics assets from its Watson Health business to investment firm Francisco Partners, the companies said Friday [January 21, 2022].

. . .

The Watson Health business uses artificial intelligence to analyze diagnostic tests and other health data and to manage care.

IBM had big aspirations for its Watson artificial intelligence to help in medical research and improve patient outcomes, but the technology’s impact has fallen short of early hopes. Partners and clients have moved away from projects that were built around Watson technology in recent years, although IBM had spent billions of dollars making acquisitions to bolster the business.

“IBM took a risk of becoming a disrupter in the complex health care industry but was only able to garner limited success,” UBS analyst David Vogt said in a note Friday.

For the full story, see:

Matt Grossman. “IBM Sells Its Watson Health Assets To Investment Firm as It Refocuses.” The Wall Street Journal (Saturday, January 22, 2022): B3.

(Note: ellipsis, and bracketed date, added.)

(Note: the online version of the story was updated Jan. 21, 2022, and has the title “IBM Sells Watson Health Assets to Investment Firm.”)

“Unprecedented” and “Huge” Serendipitous Discovery of 60 Million Icefish Nests

(p. D3) As soon as the remotely operated camera glimpsed the bottom of the Weddell Sea, more than a thousand feet below the icy ceiling at the surface, Lilian Boehringer, a student researcher at the Alfred Wegener Institute in Germany, saw the icefish nests. The sandy craters dimpled the seafloor, each the size of a hula hoop and less than a foot apart. Each crater held a single, stolid icefish, dark pectoral fins outspread like bat wings over a clutch of eggs.

Aptly named icefishes thrive in waters just above freezing with enormous hearts and blood that runs clear as vodka. . . .

The sighting occurred in February 2021 in the camera room aboard a research ship, the Polarstern, which had come to the Weddell Sea to study other things, not icefish. It was 3 a.m. near Antarctica, meaning the sun was out but most of the ship was asleep. To Ms. Boehringer’s surprise, the camera kept transmitting pictures as it moved with the ship, revealing an uninterrupted horizon of icefish nests every 20 seconds.

. . .

The nests persisted for the entire four-hour dive, with a total of 16,160 recorded on camera. After two more dives by the camera, the scientists estimated the colony of Neopagetopsis ionah icefish stretched across 92 square miles of the serene Antarctic sea, totaling 60 million active nests. The researchers described the site — the largest fish breeding colony ever discovered — in a paper published Thursday in the journal Current Biology.

“Holy cow,” said C.-H. Christina Cheng, an evolutionary biologist at the University of Illinois-Urbana-Champaign, who was not involved with the research. “This is really unprecedented,” she said. “It is crazy dense. It is a major discovery.”

. . .

“The seafloor is not just barren and boring,” Dr. Purser said. “Such huge discoveries are still there to be made, even today in the 21st century.”

For the full story, see:

Sabrina Imbler. “Deep in Frigid Waters, Icefish Colonies Thrive.” The New York Times (Tuesday, January 18, 2022): D3.

(Note: ellipses added.)

(Note: the online version of the story has the date January 13, 2022, and has the title “‘Major Discovery’ Beneath Antarctic Seas: A Giant Icefish Breeding Colony.”)

Census Bureau Algorithm Adds Noise to the Population of Monowi, Nebraska

(p. B1) The resident of Nebraska’s only one-person town was surprised when she heard the news.

The U.S. Census Bureau was reporting that Monowi’s population had exploded by 100% and was now home to two people, according to 2020 Census data it recently released.

“Well, then someone’s been hiding from me, and there’s nowhere to live but my house,” Elsie Eiler said Wednesday. “But if you find out who he is, let me know?”

His name is Noise, and he was created by an algorithm to try to protect Eiler’s personal information. Monowi didn’t add another resident to its population, but the Census Bureau did.

“What you’re seeing there is the noise we add to the data so you can’t figure out who is living there,” a bureau spokeswoman said. “It protects the privacy of the respondent and the confidentiality of the data they provide.”

The bureau doesn’t invent respondents, the spokeswoman said. But it does shift them from one census block or tract to another. And while the discrepancies might be apparent and confusing at that micro level — like when a town’s only resident is shocked to hear that she has a neighbor — the numbers are still accurate when zoomed further out, like at the congressional district level.

For the full story, see:

PETER SALTER, Lincoln Journal Star. “Monowi, Nebraska, is still a one-person town, despite what 2020 Census says.” Omaha World-Herald (Sunday, Aug. 30, 2021): B1-B2.

(Note: the online version of the story was updated Aug. 30, 2021, and has the title “Monowi, Nebraska, is still a one-person town, despite what 2020 Census says.”)

Precise Decisions Can Be Fairer (But Can You Be Precisely Wrong?)

There’s a famous quote, usually wrongly attributed to Keynes that ‘it’s better to be vaguely right than precisely wrong.’ In a new book “noise” refers to inconsistent decisions, that need not be biased in any consistent way. But consistency is not the only value that matters. Academics are sometimes evaluated on the basis of the number of articles they publish. If this is done conscientiously, then the evaluation is consistent, and in that sense “fair.” But maybe there are other criteria that are harder to measure, but that matter more, like the profundity and insight of what is published. Evaluating on the basis of well-measured criteria, that matter less, rather than poorly-measured criteria, that matter more, may increase unfairness in a deeper sense.

(p. 10) A study at an oncology center found that the diagnostic accuracy of melanomas was only 64 percent, meaning that doctors misdiagnosed melanomas in one of every three lesions.

When two psychiatrists conducted independent reviews of 426 patients in state hospitals, they came to the equivalent of a tossup: agreement 50 percent of the time on what kind of mental illness was present.

. . .

Doctors are more likely to order cancer screenings for patients they see early in the morning than late in the afternoon.

. . .

In a study of the effectiveness of putting calorie counts on menu items, consumers were more likely to make lower-calorie choices if the labels were placed to the left of the food item rather than the right.

“When calories are on the left, consumers receive that information first and evidently think ‘a lot of calories!’ or ‘not so many calories!’ before they see the item,” Daniel Kahneman, Olivier Sibony and Cass R. Sunstein explain in this tour de force of scholarship and clear writing. “By contrast, when people see the food item first, they apparently think ‘delicious!’ or ‘not so great!’ before they see the calorie label. Here again, their initial reaction greatly affects their choices.” This hypothesis is supported, the authors write in a typically clever aside, by the “finding that for Hebrew speakers, who read right to left, the calorie label has a significantly larger impact if it is on the right rather than the left.”

These inconsistencies are all about noise, which Kahneman, Sibony and Sunstein define as “unwanted variability in judgments.”

. . .

As the authors explain in their introduction, a team of target shooters whose shots always fall to the right of the bull’s-eye is exhibiting a bias, as is a judge who always sentences Black people more harshly. That’s bad, but at least they are consistent, which means the biases can be identified and corrected. But another team whose shots are scattered in different directions away from the target is shooting noisily, and that’s harder to correct. A third team whose shots all go to the left of the bull’s-eye but are scattered high and low is both biased and noisy.

Despite its prominence in so many realms of human judgment, the authors note that “noise is rarely recognized,” let alone counteracted. Which is why the parade of noise examples that the authors provide are so compelling, and why gathering the examples in one place to demonstrate the cost of noise and then suggesting noise reduction techniques, or “decision hygiene,” makes this book so important. We are living in a moment of rampant polarization and distrust in the fundamental institutions that underpin civil society. Eradicating the noise that leads to random, unfair decisions will help us regain trust in one another.

“Noise” seems certain to make a mark by calling attention to the problem and providing a tangible guide to reducing it. Despite the authors’ intimidating academic credentials, they take pains to explain, even with welcome redundancy, their various categories of noise, the experiments and formulas that they introduce, as well as their conclusions and solutions.

For the full review, see:

Steven Brill. “No Chance.” The New York Times Book Review (Sunday, May 30, 2021): 10.

(Note: ellipses added.)

(Note: the online version of the review has the date May 18, 2021, and has the title “For a Fairer World, It’s Necessary First to Cut Through the ‘Noise’.”)

The book under review is:

Kahneman, Daniel, Olivier Sibony, and Cass R. Sunstein. Noise: A Flaw in Human Judgment. New York: Little, Brown Spark, 2021.

Volatile Investor Goaded WeWork Entrepreneur “to Think Bigger”

(p. B1) Adam Neumann and Masayoshi Son were negotiating a possible $20 billion check when Mr. Son pulled up an image of Yoda on his iPad.

It was summer 2018 and Mr. Son’s tech conglomerate, SoftBank Group Corp., had already pumped over $4 billion into WeWork, the shared office space startup Mr. Neumann co-founded eight years earlier. Now Mr. Neumann was trying to get Mr. Son to buy a majority stake in WeWork. It would have been the largest acquisition ever of a startup, part of a bid to turbocharge a three-pronged strategy to dominate global real estate.

Mr. Son, a risk-taking investor who likened his gut-based strategy of “use the force” to that of the bat-eared Star Wars Jedi, was visibly excited that his new disciple was pushing for such an ambitious plan. Mr. Neumann, more than 20 years younger than Mr. Son and roughly a foot taller, charted out (p. B6) gargantuan growth projections in presentation after presentation throughout the summer. Mr. Son, scribbling on his iPad, calculated WeWork would be worth $10 trillion in a decade, more than 10 times the price tag of Apple at the time, the world’s most valuable company.

Still, Mr. Son kept urging Mr. Neumann to think bigger.

WeWork’s salespeople, real estate professionals and buildings numbered in the low hundreds. Mr. Son, though, told Mr. Neumann each category needed to grow—to 10,000. On his iPad, he commemorated the dictate.

“10k, 10k, 10k!” Mr. Son wrote in yellow, above Yoda grasping a green lightsaber. He signed below: “Masa.”

Fourteen months later, WeWork underwent one of the most spectacular corporate meltdowns of the decade.

. . .

Mr. Neumann, a long-haired, energetic entrepreneur, started WeWork after struggling to build a baby-clothes business in New York, where he moved from Israel in 2001.

. . .

Following a dinner with Walter Isaacson, biographer of Steve Jobs, he gathered staff around to read a complimentary email from the author. He told his employees he wanted Mr. Isaacson to write a biography about him.

. . .

Playing a role in Mr. Neumann’s growing ambitions was Mr. Son, who was frequently needling Mr. Neumann to think bigger.

At a meal in Tokyo with Mr. Son and Cheng Wei, CEO of Chinese ridehail giant Didi Global Inc., Mr. Son told Mr. Neumann that the Didi CEO beat out Uber Technologies Inc. in China not because he was smarter than Uber CEO Travis Kalanick. Mr. Cheng was crazier, Mr. Son said.

On the same Tokyo trip, Mr. Son asked Mr. Neumann who would win a fight between a smart guy and a crazy guy, according to people familiar with the conversation. He told Mr. Neumann that being crazy is how you win and that Mr. Neumann was not crazy enough, according to these people.

Roughly a year later at another meeting in Tokyo, Mr. Son clicked on a promotional video of SoftBank-backed Oyo Hotels & Homes, led by the then 24-year-old Ritesh Agarwal. Oyo was growing far faster than WeWork, Mr. Son told Mr. Neumann, ribbing him about lagging behind his SoftBank-backed counterpart, whom Mr. Son equated with a sibling.

“Your little brother is going to beat you,” Mr. Son told Mr. Neumann, according to people familiar with the conversation. “He is being bolder than you.”

Following meetings like this, Mr. Neumann often pushed for bigger ideas, aides said.

For the full commentary, see:

Eliot Brown and Maureen Farrell. “The We That Didn’t Work.” The Wall Street Journal (Saturday, July 17, 2021): B1 & B6.

(Note: ellipses added.)

(Note: the online version of the commentary has the same date as the print version, and has the title “The We That Didn’t Work at WeWork.”)

The commentary quoted above is based on the authors’ book:

Brown, Eliot, and Maureen Farrell. The Cult of We: WeWork, Adam Neumann, and the Great Startup Delusion. New York: Crown, 2021.

Dreams May Be a Byproduct of Brain Repair, Without Deep Meaning

(p. 20) Dr. J. Allan Hobson, a psychiatrist and pioneering sleep researcher who disputed Freud’s view that dreams held hidden psychological meaning, died on July 7 [2021] at his home in East Burke, Vt.

. . .

“He showed that sleep isn’t a nothing state,” Ralph Lydic, who conducted research with Dr. Hobson in the 1980s and is a professor of neuroscience at the University of Tennessee, said in a phone interview.

“He demonstrated that the brain is as active during R.E.M. sleep as it is during wakefulness,” he added, referring to sleep characterized by rapid eye movement. “We know as much about sleep as we do in part because of him.”

One of his most influential contributions to dream research came in 1977, when Dr. Hobson and a colleague, Robert McCarley, produced a cellular and mathematical model that they believed showed how dreams occur. Dreams, they said, are not mysterious codes sent by the subconscious but rather the brain’s attempt to attribute meaning to random firings of neurons in the brain.

This view, that dreams are the byproduct of chemical reactions, was a departure from psychological orthodoxy and heresy to Freudians, and it remains in dispute.

But to Dr. Hobson, the content of dreams was not as important as the electrical activity of the brain during the dream state.

. . .

“I’m skeptical about any absolute set of rules, scientific rules, moral rules, behavioral rules,” he said in a 2011 interview with The Boston Globe.

For the full obituary, see:

Katharine Q. Seelye. “J. Allan Hobson, 88, Who Took Sleep Seriously, Dies.” The New York Times, First Section (Sunday, August 1, 2021): 20.

(Note: ellipses, and bracketed year, added.)

(Note: the online version of the obituary has the date July 28, 2021, and has the title “Dr. J. Allan Hobson, Who Studied the Dreaming Brain, Dies at 88.”)

Auerbach Talked to Hikers, Skiers, and Divers to Advance Wilderness Medicine: “He Never Stopped”

(p. B10) Dr. Paul Auerbach, an emergency care physician who pioneered the field of wilderness medicine in the 1980s and then taught ways to heal people injured by the unpredictable, died on June 23 [2021] at his home in Los Altos, Calif.

. . .

Out in the wild, knowing how to treat a venomous snake bite or a gangrenous infection can mean the difference between life and death. In the 1970s, however, the specialized field of health care known as wilderness medicine was still in its infancy. Then Dr. Auerbach showed up.

A medical student at Duke University at the time, he went to work in 1975 with the Indian Health Service on a Native American reservation in Montana, and the experience was revelatory.

“We saw all kinds of cases that I would have never seen at Duke or frankly anywhere else except on the reservation,” Dr. Auerbach said in a recent interview given to Stanford University, where he worked for many years. “Snakebites. Drowning. Lightning strike.”

. . .

“I kept going back to literature to read, but there was no literature,” he said. “If I wanted to read about snake bites, I was all over the place. If I wanted to read about heat illness, I was all over the place. So I thought, ‘Huh, maybe I’ll do a book on wilderness medicine.’”

Dr. Auerbach started researching material for the book in 1978, when he began his medical residency at U.C.L.A., finding the time to do so despite grueling 12-hour hospital shifts. He collected information about how to treat burn wounds, hypothermia, frostbite and lightning injuries. He interviewed hikers, skiers and divers. And he assigned chapters to doctors who were passionate about the outdoors.

The resulting book, “Management of Wilderness and Environmental Emergencies,” which he edited with a colleague, Edward Geehr, was published in 1983 and is widely considered the definitive textbook in the field, with sections like “Protection From Blood-Feeding Arthropods” and “Aerospace Medicine: The Vertical Frontier.” Updated by Dr. Auerbach over 30 years, it is in its seventh edition and now titled “Auerbach’s Wilderness Medicine.”

. . .

Last year, shortly before he received his cancer diagnosis, the coronavirus pandemic began to take hold, and Dr. Auerbach decided to act.

“The minute it all first happened, he started working on disaster response,” his wife said. “Hospitals were running out of PPE. He was calling this person and that person to learn as much as he could. He wanted to find out how to design better masks and better ventilators. He never stopped.”

For the full obituary, see:

Alex Vadukul. “Dr. Paul Auerbach, 70, Who Pioneered Treatment of Wilderness Emergencies.” The New York Times, First Section (Tuesday, July 20, 2021): B10.

(Note: ellipses, and bracketed year, added.)

(Note: the online version of the obituary has the date July 19, 2021, and has the title “Dr. Paul Auerbach, Father of Wilderness Medicine, Dies at 70.”)

The latest edition of Auerbach’s book is:

Auerbach, Paul S., Tracy A. Cushing, and N. Stuart Harris, eds. Auerbach’s Wilderness Medicine. 7th ed. 2 vols. Philadelphia, PA: Elsevier, 2017.

Labrador Noses May Be Cheaper and More Accurate Than Rapid Antigen Test at Detecting Covid-19

(p. A1) . . . three Labradors, operating out of a university clinic in Bangkok, are part of a global corps of dogs being trained to sniff out Covid-19 in people. Preliminary studies, conducted in multiple countries, suggest that their detection rate may surpass that of the rapid antigen testing often used in airports and other public places.

. . .

(p. A6) . . . as a group, the dogs being trained in Thailand — Angel, Bobby, Bravo and three others, Apollo, Tiger and Nasa — accurately detected the virus 96.2 percent of the time in controlled settings, according to university researchers. Studies in Germany and the United Arab Emirates had lower but still impressive results.

Sniffer dogs work faster and far more cheaply than polymerase chain reaction, or P.C.R., testing, their proponents say. An intake of air through their sensitive snouts is enough to identify within a second the volatile organic compound or cocktail of compounds that are produced when a person with Covid-19 sheds damaged cells, researchers say.

“P.C.R. tests are not immediate, and there are false negative results, while we know that dogs can detect Covid in its incubation phase,” said Dr. Anne-Lise Chaber, an interdisciplinary health expert at the School of Animal and Veterinary Sciences at the University of Adelaide in Australia who has been working for six months with 15 Covid-sniffing dogs.

Some methods of detection, like temperature screening, can’t identify infected people who have no symptoms. But dogs can, because the infected lungs and trachea produce a trademark scent. And dogs need fewer molecules to nose out Covid than are required for P.C.R. testing, Thai researchers said.

The Thai Labradors are part of a research project run jointly by Chulalongkorn University and Chevron. The oil company had previously used dogs to test its offshore employees for illegal drug use, and a Thai manager wondered whether the animals could do the same with the coronavirus.

. . .

Dogs, whose wet snouts have up to 300 million olfactory receptors compared with roughly six million for humans, can be trained to memorize about 10 smell patterns for a specific compound, Dr. Kaywalee said. Dogs can also smell through another organ nestled between their noses and mouths.

Some research has suggested that dogs of various breeds may be able to detect diabetes, Parkinson’s disease, malaria and certain cancers — that is, the volatile organic compounds or bodily fluids associated with them.

Labradors are among the smartest breeds, said Lertchai Chaumrattanakul, who leads Chevron’s part of the dog project. They are affable, too, making them the ideal doggy detector: engaged and eager.

Mr. Lertchai noted that Labradors are expensive, about $2,000 each in Thailand. But the cotton swabs and other basic equipment for canine testing work out to about 75 cents per sample. That is much cheaper than what’s needed for other types of rapid screening.