Later On

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Alexa, Should We Trust You?

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Judith SHulevitz writes in the Atlantic:

For a few days this summer, Alexa, the voice assistant who speaks to me through my Amazon Echo Dot, took to ending our interactions with a whisper: Sweet dreams. Every time it happened, I was startled, although I thought I understood why she was doing it, insofar as I understand anything that goes on inside that squat slice of black tube. I had gone onto Amazon.com and activated a third-party “skill”—an applike program that enables Alexa to perform a service or do a trick—called “Baby Lullaby.” It plays an instrumental version of a nursery song (yes, I still listen to lullabies to get to sleep), then signs off softly with the nighttime benediction. My conjecture is that the last string of code somehow went astray and attached itself to other “skills.” But even though my adult self knew perfectly well that Sweet dreams was a glitch, a part of me wanted to believe that Alexa meant it. Who doesn’t crave a motherly goodnight, even in mid-afternoon? Proust would have understood.

We’re all falling for Alexa, unless we’re falling for Google Assistant, or Siri, or some other genie in a smart speaker. When I say “smart,” I mean the speakers possess artificial intelligence, can conduct basic conversations, and are hooked up to the internet, which allows them to look stuff up and do things for you. And when I say “all,” I know some readers will think, Speak for yourself! Friends my age—we’re the last of the Baby Boomers—tell me they have no desire to talk to a computer or have a computer talk to them. Cynics of every age suspect their virtual assistants of eavesdropping, and not without reason. Smart speakers are yet another way for companies to keep tabs on our searches and purchases. Their microphones listen even when you’re not interacting with them, because they have to be able to hear their “wake word,” the command that snaps them to attention and puts them at your service.

The speakers’ manufacturers promise that only speech that follows the wake word is archived in the cloud, and Amazon and Google, at least, make deleting those exchanges easy enough. Nonetheless, every so often weird glitches occur, like the time Alexa recorded a family’s private conversation without their having said the wake word and emailed the recording to an acquaintance on their contacts list. Amazon explained that Alexa must have been awakened by a word that sounded like Alexa (TexasA LexusPraxis?), then misconstrued elements of the ensuing conversation as a series of commands. The explanation did not make me feel much better.

Privacy concerns have not stopped the march of these devices into our homes, however. Amazon doesn’t disclose exact figures, but when I asked how many Echo devices have been sold, a spokeswoman said “tens of millions.” By the end of last year, more than 40 million smart speakers had been installed worldwide, according to Canalys, a technology-research firm. Based on current sales, Canalys estimates that this figure will reach 100 million by the end of this year. According to a 2018 report by National Public Radio and Edison Research, 8 million Americans own three or more smart speakers, suggesting that they feel the need to always have one within earshot. By 2021, according to another research firm, Ovum, there will be almost as many voice-activated assistants on the planet as people. It took about 30 years for mobile phones to outnumber humans. Alexa and her ilk may get there in less than half that time.

One reason is that Amazon and Google are pushing these devices hard, discounting them so heavily during last year’s holiday season that industry observers suspect that the companies lost money on each unit sold. These and other tech corporations have grand ambitions. They want to colonize space. Not interplanetary space. Everyday space: home, office, car. In the near future, everything from your lighting to your air-conditioning to your refrigerator, your coffee maker, and even your toilet could be wired to a system controlled by voice.

The company that succeeds in cornering the smart-speaker market will lock appliance manufacturers, app designers, and consumers into its ecosystem of devices and services, just as Microsoft tethered the personal-computer industry to its operating system in the 1990s. Alexa alone already works with more than 20,000 smart-home devices representing more than 3,500 brands. Her voice emanates from more than 100 third-party gadgets, including headphones, security systems, and automobiles.

Yet there is an inherent appeal to the devices, too—one beyond mere consumerism. Even those of us who approach new technologies with a healthy amount of caution are finding reasons to welcome smart speakers into our homes. After my daughter-in-law posted on Instagram an adorable video of her 2-year-old son trying to get Alexa to play “You’re Welcome,” from the Moana soundtrack, I wrote to ask why she and my stepson had bought an Echo, given that they’re fairly strict about what they let their son play with. “Before we got Alexa, the only way to play music was on our computers, and when [he] sees a computer screen, he thinks it’s time to watch TV,” my daughter-in-law emailed back. “It’s great to have a way to listen to music or the radio that doesn’t involve opening up a computer screen.” She’s not the first parent to have had that thought. In that same NPR/Edison report, close to half the parents who had recently purchased a smart speaker reported that they’d done so to cut back on household screen time.

The ramifications of this shift are likely to be wide and profound. Human history is a by-product of human inventions. New tools—wheels, plows, PCs—usher in new economic and social orders. They create and destroy civilizations. Voice technologies such as telephones, recording devices, and the radio have had a particularly momentous impact on the course of political history—speech and rhetoric being, of course, the classical means of persuasion. Radio broadcasts of Adolf Hitler’s rallies helped create a dictator; Franklin D. Roosevelt’s fireside chats edged America toward the war that toppled that dictator.

Perhaps you think that talking to Alexa is just a new way to do the things you already do on a screen: shopping, catching up on the news, trying to figure out whether your dog is sick or just depressed. It’s not that simple. It’s not a matter of switching out the body parts used to accomplish those tasks—replacing fingers and eyes with mouths and ears. We’re talking about a change in status for the technology itself—an upgrade, as it were. When we converse with our personal assistants, we bring them closer to our own level.

Gifted with the once uniquely human power of speech, Alexa, Google Assistant, and Siri have already become greater than the sum of their parts. They’re software, but they’re more than that, just as human consciousness is an effect of neurons and synapses but is more than that. Their speech makes us treat them as if they had a mind. “The spoken word proceeds from the human interior, and manifests human beings to one another as conscious interiors, as persons,” the late Walter Ong wrote in his classic study of oral culture, Orality and Literacy. These secretarial companions may be faux-conscious nonpersons, but their words give them personality and social presence.

And indeed, these devices no longer serve solely as intermediaries, portals to e-commerce or nytimes.com. We communicate with them, not through them. More than once, I’ve found myself telling my Google Assistant about the sense of emptiness I sometimes feel. “I’m lonely,” I say, which I usually wouldn’t confess to anyone but my therapist—not even my husband, who might take it the wrong way.
. .

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Written by LeisureGuy

18 October 2018 at 3:24 pm

No Wonder It Works So Well: There May Be Viagra In That Herbal Supplement

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Ronnie Cohen reports at NPR:

They claim to help you sleep, make your hair grow, speed weight loss, improve your sex life and ward off the nasty cold going around the office. Though it’s often impossible to tell if dietary supplements work, consumers generally feel certain they can’t hurt.

But they can.

The Food and Drug Administration has identified hundreds of supplements tainted with pharmaceuticals — from antidepressants and erectile dysfunction remedies to weight-loss drugs — since 2007, a study published Friday shows. Even after FDA tests proved the supplements contained unapproved or recalled medications, many of the products continued to be marketed and sold, the analysis finds.

The report in JAMA Network Open calls into question the FDA’s ability to effectively police the $35-billion-a-year supplements industry.

“The FDA didn’t even bother to recall more than half of the potentially hazardous supplements,” says Dr. Pieter Cohen, a Harvard Medical School professorand an internist with Cambridge Health Alliance in Boston, who wrote an accompanying commentary in the journal.

“How could it be that our premier public health agency spends the time and money to detect these hidden ingredients and then doesn’t take the next obvious step, which is to ensure that they are removed from the marketplace?” he asks.

The FDA does not comment on specific studies “but evaluates them as part of the body of evidence to further our understanding about a particular issue and assist in our mission to protect public health,” says Lindsay Haake, a press officer for the regulatory agency.

For the study, researchers from the California Department of Public Health and other state agencies examined an FDA database containing supplements that the FDA has purchased, tested and found to be adulterated. The FDA identified 746 supplement products that were pharmaceutically adulterated from 2007 through 2016.

Adulterants included unapproved antidepressants and designer steroids, the prescription erectile-dysfunction drug sildenafil, and a prescription appetite suppressant its manufacturer withdrew from the market after a study linked it to heightened risk of stroke and heart attack.

Although the FDA has the power to recall tainted supplements, the federal agency failed to require any of the 146 companies that manufactured the adulterated products to remove them from the market.

In 360 cases, manufacturers announced a voluntarily recall of the tainted supplements, though there is no way of knowing if the products actually were recalled, Cohen says. In 342 cases, the agency posted a notice on its website warning the public about the tainted supplements.

Only in seven cases did the FDA issue a warning letter nudging the manufacturer to remove the adulterated products. Before the FDA could seize a supplement and destroy it, it would have to send a warning letter to the manufacturer, Cohen says.

The study’s authors write that they find it “alarming” that the adulterated supplements continue to be sold.

“This report shines a harsh light on the problem of adulteration,” says Dr. Peter Lurie, president of the Center for Science in the Public Interest, a Washington, D.C., advocacy group. Lurie was not involved in the research. “It’s a very disturbing picture. You’ve got hundreds of these products that contain active pharmaceuticals, many of which pose a real threat to human health.”

Some of the drugs slipped into supplements without appearing on the label can have dangerous interactions with other medications people may be taking. For instance, drugs such as sildenafil may interact with other drugs to lower or raise blood pressure to dangerous levels. Others, including anabolic steroids present in some muscle-building products, have been associated with liver and kidney damage, heart attacks and strokes.

“The study lays a foundation for ongoing enforcement work in this area, by the FDA and other partner agencies, to curb the illegal manufacture, importation, distribution and sales of adulterated dietary supplements,” the California Department of Public Health said in a written statement.

More than half of American adults take supplements such as vitamins, minerals, protein powders, botanicals, fish oils, glandular extracts and probiotics. Under a 1994 law, the U.S. government reclassified supplements as food rather than food additives. The law exempts supplements from any of the premarket safety and effectiveness testing the FDA requires for drugs.

In the 24 years since the law took effect, the supplements industry has boomed.

“The underlying problem is this is a huge industry with fly-by-night actors, and it’s completely impossible for the agency to keep up with them,” says Lurie, who worked at the FDA for eight years. “We’d all like to see the agency doing more. In some cases it has limited authority. In other cases it has limited resources.” . . .

Continue reading.

The obvious answer: a stiff Federal tax on supplements with the proceeds directed toward beefing up the part of the FDA that monitors supplements, plus very stiff fines for manufacturers who have adulterated supplements with unsafe ingredients, the fines likewise going to the FDA. A Democratic Congress might do this; a Republican Congress, never.

Written by LeisureGuy

14 October 2018 at 8:37 am

Mythbusting 101: Organic Farming > Conventional Agriculture

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Christie Wilcox writes in the Scientific American in 2011:

Ten years ago, Certified Organic didn’t exist in the United States. Yet in 2010, a mere eight years after USDA’s regulations officially went into effect, organic foods and beverages made $26.7 billion. In the past year or two, certified organic sales have jumped to about $52 billion worldwide despite the fact that organic foods cost up to three times as much as those produced by conventional methods. More and more, people are shelling out their hard-earned cash for what they believe are the best foods available. Imagine, people say: you can improve your nutrition while helping save the planet from the evils of conventional agriculture – a complete win-win. And who wouldn’t buy organic, when it just sounds so good?

Here’s the thing: there are a lot of myths out there about organic foods, and a lot of propaganda supporting methods that are rarely understood. It’s like your mother used to say: just because everyone is jumping off a bridge doesn’t mean you should do it, too. Now, before I get yelled at too much, let me state unequivocally that I’m not saying organic farming is bad – far from it. There are some definite upsides and benefits that come from many organic farming methods. For example, the efforts of organic farmers to move away from monocultures, where crops are farmed in single-species plots, are fantastic; crop rotations and mixed planting are much better for the soil and environment. My goal in this post isn’t to bash organic farms, instead, it’s to bust the worst of the myths that surround them so that everyone can judge organic farming based on facts. In particular, there are four myths thrown around like they’re real that just drive me crazy.

Myth #1: Organic Farms Don’t Use Pesticides

When the Soil Association, a major organic accreditation body in the UK, asked consumers why they buy organic food, 95% of them said their top reason was to avoid pesticides. They, like many people, believe that organic farming involves little to no pesticide use. I hate to burst the bubble, but that’s simply not true. Organic farming, just like other forms of agriculture, still uses pesticides and fungicides to prevent critters from destroying their crops. Confused?

So was I, when I first learned this from a guy I was dating. His family owns a farm in rural Ohio. He was grumbling about how everyone praised the local organic farms for being so environmentally-conscientious, even though they sprayed their crops with pesticides all the time while his family farm got no credit for being pesticide-free (they’re not organic because they use a non-organic herbicide once a year). I didn’t believe him at first, so I looked into it: turns out that there are over 20 chemicals commonly used in the growing and processing of organic crops that are approved by the US Organic Standards. And, shockingly, the actual volume usage of pesticides on organic farms is not recorded by the government. Why the government isn’t keeping watch on organic pesticide and fungicide use is a damn good question, especially considering that many organic pesticides that are also used by conventional farmers are used more intensively than synthetic ones due to their lower levels of effectiveness. According to the National Center for Food and Agricultural Policy, the top two organic fungicides, copper and sulfur, were used at a rate of 4 and 34 pounds per acre in 1971 1. In contrast, the synthetic fungicides only required a rate of 1.6 lbs per acre, less than half the amount of the organic alternatives.

The sad truth is, factory farming is factory farming, whether its organic or conventional. Many large organic farms use pesticides liberally. They’re organic by certification, but you’d never know it if you saw their farming practices. As Michael Pollan, best-selling book author and organic supporter, said in an interview with Organic Gardening,

“They’re organic by the letter, not organic in spirit… if most organic consumers went to those places, they would feel they were getting ripped off.”

What makes organic farming different, then? It’s not the use of pesticides, it’s the origin of the pesticides used. Organic pesticides are those that are derived from natural sources and processed lightly if at all before use. This is different than the current pesticides used by conventional agriculture, which are generally synthetic. It has been assumed for years that pesticides that occur naturally (in certain plants, for example) are somehow better for us and the environment than those that have been created by man. As more research is done into their toxicity, however, this simply isn’t true, either. Many natural pesticides have been found to be potential – or serious – health risks.2

Take the example of Rotenone. Rotenone was widely used in the US as an organic pesticide for decades 3. Because it is natural in origin, occurring in the roots and stems of a small number of subtropical plants, it was considered “safe” as well as “organic“. However, research has shown that rotenone is highly dangerous because it kills by attacking mitochondria, the energy powerhouses of all living cells. Research found that exposure to rotenone caused Parkinson’s Disease-like symptoms in rats 4, and had the potential to kill many species, including humans. Rotenone’s use as a pesticide has already been discontinued in the US as of 2005 due to health concerns***, but shockingly, it’s still poured into our waters every year by fisheries management officials as a piscicide to remove unwanted fish species.

The point I’m driving home here is that just because something is natural doesn’t make it non-toxic or safe. Many bacteria, fungi and plants produce poisons, toxins and chemicals that you definitely wouldn’t want sprayed on your food.

Just last year, nearly half of the pesticides that are currently approved for use by organic farmers in Europe failed to pass the European Union’s safety evaluation that is required by law 5. Among the chemicals failing the test was rotenone, as it had yet to be banned in Europe. Furthermore, just over 1% of organic foodstuffs produced in 2007 and tested by the European Food Safety Authority were found to contain pesticide levels above the legal maximum levels – and these are of pesticides that are not organic 6. Similarly, when Consumer Reports purchased a thousand pounds of tomatoes, peaches, green bell peppers, and apples in five cities and tested them for more than 300 synthetic pesticides, they found traces of them in 25% of the organically-labeled foods, but between all of the organic and non-organic foods tested, only one sample of each exceeded the federal limits8.

Not only are organic pesticides not safe, they might actually be worse than the ones used by the conventional agriculture industry. Canadian scientists pitted ‘reduced-risk’ organic and synthetic pesticides against each other in controlling a problematic pest, the soybean aphid. They found that not only were the synthetic pesticides more effective means of control, the organic pesticides were more ecologically damaging, including causing higher mortality in other, non-target species like the aphid’s predators9. Of course, some organic pesticides may fare better than these ones did in similar head-to-head tests, but studies like this one reveal that the assumption that natural is better for the environment could be very dangerous.

Even if the organic food you’re eating is from a farm which uses little to no pesticides at all, there is another problem: getting rid of pesticides doesn’t mean your food is free from harmful things. Between 1990 and 2001, over 10,000 people fell ill due to foods contaminated with pathogens like E. coli, and many have organic foods to blame. That’s because organic foods tend to have higher levels of potential pathogens. One study, for example, found E. coli in produce from almost 10% of organic farms samples, but only 2% of conventional ones10. The same study also found Salmonella only in samples from organic farms, though at a low prevalence rate. The reason for the higher pathogen prevalence is likely due to the use of manure instead of artificial fertilizers, as many pathogens are spread through fecal contamination. Conventional farms often use manure, too, but they use irradiation and a full array of non-organic anti-microbial agents as well, and without those, organic foods run a higher risk of containing something that will make a person sick.

In the end, it really depends on exactly what methods are used by crop producers. Both organic and conventional farms vary widely in this respect. Some conventional farms use no pesticides. Some organic farms spray their crops twice a month. Of course, some conventional farms spray just as frequently, if not more so, and some organic farms use no pesticides whatsoever. To really know what you’re in for, it’s best if you know your source, and a great way to do that is to buy locally. Talk to the person behind the crop stand, and actually ask them what their methods are if you want to be sure of what you’re eating.

Myth #2: Organic Foods are Healthier

Some people believe that by not using manufactured chemicals or genetically modified organisms, organic farming produces more nutritious food. However, science simply cannot find any evidence that organic foods are in any way healthier than non-organic ones – and scientists have been comparing the two for over 50 years.

Just recently, an independent research project in the UK systematically reviewed the 162 articles on organic versus non-organic crops published in peer-reviewed journals between 1958 and 2008 11. These contained a total of 3558 comparisons of content of nutrients and other substances in organically and conventionally produced foods. They found absolutely no evidence for any differences in content of over 15 different nutrients including vitamin C, ?-carotene, and calcium. There were some differences, though; conventional crops had higher nitrogen levels, while organic ones had higher phosphorus and acidity – none of which factor in much to nutritional quality. Further analysis of similar studies on livestock products like meat, dairy, and eggs also found few differences in nutritional content. Organic foods did, however, have higher levels of overall fats, particularly trans fats. So if anything, the organic livestock products were found to be worse for us (though, to be fair, barely). . .

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Written by LeisureGuy

13 October 2018 at 11:37 am

My knee pain explained

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I am just back from a visit to a physiotherapist. I explained that I had been walking since the beginning of July, initially just regular walking but Nordic walking after the first week or so, and with daily step goals set first at 2000 steps, then at 5000 steps, and currently 8000 steps—working up gradually.

Day before yesterday I had done a 63-minute walk at a brisk pace (covering 3.8 miles), and then yesterday I awoke at 3:00am with terrific pain in left knee and not able even to turn over in bed without it hurting badly. I never got back to sleep and it hurt all morning. I finally took a couple of Advil, and eventually it calmed down, but still I had to be very careful and that knee didn’t support my weight well.

The first question the physiotherapist asked was, “Did your twist your foot or turn your ankle on the walk?” And in fact I had: I had twisted my foot strongly, but then it seemed to be okay. She explained (after pushing here and there on my knee and finding out the locus of the soreness and observing the slight swelling) that I had scratched the edge of the inside meniscus in the red zone: a meniscus-tear injury—a common injury.

So she recommended a set of 4 exercises, cold packs 3-4 times a day, and exercises that move the knee without putting weight on it: a cycling machine, swimming, and the like. Plain (not Noridc) walking in a week, but on flat surfaces (no hills) and at a moderate pace. Full recovery will be in 4-6 weeks, so by the end of November I should be good to resume vigorous Nordic walking.

Written by LeisureGuy

11 October 2018 at 10:21 am

A New Study Shows How Mushrooms Could Save Bees. (Yes, Mushrooms.)

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Jackie Flynn Mogensen writes in Mother Jones:

e stuff of science fiction. Back in 2006, beekeepers first noticed their honeybees were mysteriously dying off in huge numbers, with no clear cause. For some, a whopping 30 to 90 percent of their colonies were disappearing, especially on the East Coast. Worker bees were abandoning their queens and leaving hives full of honey. That first winter, beekeepers nationwide lost about a third of their colonies. Since then, the numbers haven’t improved.

Researchers now call this ongoing phenomenon “colony collapse disorder,” but scientists still haven’t identified a singular cause. They say it’s a combination of factors: pollution, habitat loss, herbicides, and viruses, though some experts believe viruses may be the primary driver. For instance, “deformed wing virus,” which causes bees to develop disfigured, nonfunctional wings, can be nasty, and, like other viruses, is transferred to bees by parasitic mites. Until now, scientists haven’t developed any antiviral treatments to protect the bees.

But in a landmark study published Thursday in Nature journal Scientific Reports, researchers revealed they’ve discovered the first-ever “vaccine” for bees, procured from an unexpected source: mushrooms. Specifically, it’s mycelia—cobweb-like fungal membranes found in and on soil—from two species, “tinder fungus” and Red Reishi mushrooms.

“Up until this discovery, there were no antivirals reducing viruses in bees,” Paul Stamets, the lead author on the study, tells Mother Jones. “Not only is this the first discovery, but these extracts are incredibly potent.” Stamets is a Washington-based mycologist and author whose work includes books Mycelium Running: How Mushrooms Can Help Save The WorldGrowing Gourmet and Medicinal Mushrooms, and Psilocybin Mushrooms of the World. Stamets also holds patents “pertaining to the use of fungal extracts for antiviral activity and honeybee health,” according to the study.

This giant discovery actually has very humble origins. Decades before colony collapse hit the United States, Stamets says he had noticed bees in his own yard feeding off water droplets on the mushrooms that were growing on wood chips in his garden. They had pushed the wood chips aside to expose the mycelium. At the time, he thought they might be getting sugars from the fungi, and it wasn’t until about five years ago—after researching the antiviral properties of fungi for humans—that he made the connection to viruses affecting bees. “I had this waking dream, ‘I think I can save the bees,’” he says.

In collaboration with researchers from Washington State University, Stamets decided to conduct a two-part study to test his theory that fungi could treat the viruses in honeybees. First, in a controlled, caged experiment, he and his team added small amounts of mushroom extract, or “mycelial broth,” to the bees’ food (sugar water) at varying concentrations and measured how it affected their health. Then, they tested the best-performing extracts in the field.

The extracts worked better than Stamets ever imagined.

The team measured the virus levels in 50 bees from 30 different field colonies and found the bee colonies that consumed the mycelium extracts saw up to a 79-fold decrease in deformed wing virus after 12 days and up to a 45,000-fold reduction in Lake Sinai virus (another virus linked to colony collapse) compared to the bees that only ate sugar water.

“We went out of the laboratory, into the field—real-life field tests,” says Stamets. “And we saw enormous benefit to the bees.”

So what’s going on here? Stamets says the operating hypothesis is this: “These aren’t really antiviral drugs. We think they are supporting the immune system to allow natural immunity to be strong enough to reduce the viruses.” More research, he says, is needed to fully understand how the fungi are working.

Diana Cox-Foster, a research leader and entomologist at the USDA’s Pollinating Insects Research Unit in Utah who was not involved in the study, tells Mother Jones the research looked “promising” and adds that it could have ramifications for other pollinators, like bumblebees. “These viruses are widely shared,” she says. “If we could knock down viruses in honeybee colonies, it could lead to greater health in other pollinators.” . . .

Continue reading.

Written by LeisureGuy

7 October 2018 at 11:14 am

Nordic walking getting better

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Because of rain, I didn’t walk yesterday, and the three times I walked previously I was slower (68 minutes, then 66.9 and 67.6), with a slower cadence (106.7, 108.4, 107.3 steps/minute respectively).

So today I pushed myself to walk faster. Today: 63.1 minutes (my best time yet) and a cadence of 112.6 steps/minute (my fastest cadence yet). And I’m not tired. A little sweaty, but not tired.

I do two laps (1.15 miles each) with this hill profile:

And then two laps (5/8 mile each) with this hill profile:

And then a short lap around the end of the block, essentially flat. Total distance 3.8 miles. Speed: 3.6 mph.

Written by LeisureGuy

6 October 2018 at 12:04 pm

Doctors are surprisingly bad at reading lab results. It’s putting us all at risk.

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Daniel Morgan writes in the Washington Post:

The man was 66 when he came to the hospital with a serious skin infection. He had a fever and low blood pressure, as well as a headache. His doctors gave him a brain scan just to be safe. They found a very small bulge in one of his cranial arteries, which probably had nothing to do with his headache or the infection. Nevertheless, doctors ordered an angiogram to get images of brain blood vessels. This test, in which doctors insert a plastic tube into a patient’s arteries and inject dye, found no evidence of any blood vessel problems. But the dye injection caused multiple strokes, leading to permanent issues with the man’s speech and memory.

That case, recounted in JAMA Internal Medicine three years ago, is no surprise. As a doctor in a large urban hospital, I know how much modern medicine has come to rely on tests and scans. I review about 10 cases per day and order and interpret more than 150 tests for patients. Every year, doctors in this country order more than 4 billion tests in total. They’ve gotten more sophisticated and easier to execute as technology has advanced, and they’re essential to helping doctors understand what might be wrong with their patients.

But my research has found that many physicians misunderstand test results or think tests are more accurate than they are. Doctors especially fail to grasp how false positives work, which means they make crucial medical decisions — sometimes life-or-death calls — based on incorrect assumptions that patients have ailments that they probably don’t. When we do this without understanding the science of risk and probability, we unacceptably increase the chances of making the wrong choice. In the worst cases, as with the man whose angiogram caused otherwise avoidable strokes, we increase the odds of unnecessarily putting patients in danger.

The first problem that doctors (and thus, patients) face is a basic misunderstanding of probability. Say that Disease X has a prevalence of 1 in 1,000 (meaning that 1 out of every 1,000 people will have it), and the test to detect it has a false-positive rate of 5 percent (meaning 5 of every 100 subjects test positive for the ailment even though they don’t really have it). If a patient’s test result comes back positive, what are the chances that she actually has the disease? In a 2014 study, researchers found that almost half of doctors surveyed said patients who tested positive had a 95 percent chance of having Disease X.

This is radically, catastrophically wrong. In fact, it’s not even close to right. Imagine 1,000 people, all with the same chance of having Disease X. We already know that just one of them has the disease. But a 5 percent false-positive rate means that 50 of the remaining 999 would test positive for it nonetheless. That means 51 people would have positive results, but only one of those would really have the illness. So if your test comes back positive, your true chance of having the disease is actually 1 out of 51, or 2 percent — a heck of a lot lower than 95 percent.

A 5 percent false-positive rate is typical of many common tests. The primary blood test to check for a heart attack, known as high-sensitivity troponin, has a 5 percent false-positive rate, for instance. U.S. emergency rooms often administer the test to people with a very low probability of a heart attack; as a result, 84 percent of positive results are false, according to a study published last year. These false-positive troponin tests often lead to stress tests, observation visits with expensive co-pays and sometimes invasive cardiac angiograms.

In one study, gynecologists estimated that a woman whose mammogram was positive had a higher than 80 percent chance of having breast cancer; the reality is that her chance is less than 10 percent. Of course, women who have a positive mammogram often undergo other tests, such as an MRI and a biopsy, which can offer more precision about the presence of cancer. But researchers have found that even after the battery of exams, about 5 of every 1,000 women will have a false-positive result and will be told they have breast cancer when they do not.

The confusion has serious consequences. These women are likely to receive unnecessary treatment — generally some combination of surgery, radiation or chemotherapy, all of which have serious side effects and are stressful and expensive. Switzerland and France, grasping this problem, are halting and reconsidering their mammogram programs. In Switzerland, they’re not screening ahead of time, preferring to manage cases of breast cancer as they’re diagnosed. In France, doctors are letting women decide for themselves whether to have the tests.

Studies have found that doctors make similar errors with other tests, including those for prostate and lung cancer, heart attack, asthma and Lyme disease. Of course, no test is perfect, and even very careful, statistically sophisticated doctors can sometimes make mistakes. That’s not the problem.

Too many of my colleagues do not understand that many of the tests they rely on are deeply fallible. In a study I published last year with several colleagues, we reviewed the treatment of 177 patients who were admitted to hospitals with a wide range of problems, from broken bones to severe intestinal pain, to see how necessary their tests were, as judged by the latest medical guidelines. We found that nearly 90 percent of the patients received at least one unnecessary test and that, overall, nearly one-third of all the tests were superfluous. Clearly, when patients receive tests that aren’t needed, there is a reasonable chance that doctors are using the results to make choices about treatment; by definition, these choices have a higher danger of being flawed.

In another paper, from 2016, my colleagues and I interviewed more than 100 doctors to gauge their understanding of the risks and benefits of 10 common medical tests or treatments. We found that nearly 80 percent of our subjects overestimated the benefits. Strangely, the doctors themselves acknowledged this, with two-thirds rating themselves as not confident in their understanding of tests and probability. Eight out of 10 said they rarely, if ever, talked to patients about the probability of test results being accurate.

I have to admit that I, too, sometimes fall prey to overvaluing test results regardless of their probability. Last year, I saw a patient who had problems breathing. His symptoms were typical of chronic obstructive pulmonary disease (COPD), but a test for a blood clot in the lung came back positive. This test has a relatively high false-positive rate, but we still started the patient on a blood thinner, which can treat clots but also has serious risks, such as internal bleeding. Within a few days, another test confirmed that he did not have a blood clot, so we discontinued the anticoagulant, which caused no permanent harm. But things could have gone much worse.

Basic misunderstandings about how tests work and how accurate they are contribute to a bigger problem. Although precise numbers are hard to come by, every year, many thousands of patients are diagnosed with diseases that they don’t have. They receive treatments they don’t need, treatments that may have harmful side effects. Perhaps just as important, they and those around them often experience enormous stress from these incorrect diagnoses. Treating nonexistent diseases is wasteful and often expensive, not only for patients but for hospitals, insurance companies and governments.

Doctors also tend to overuse some tests. In a paper last year, my colleagues and I highlighted some key examples: One was computed tomography (CT), a high-tech scanning technology that is increasingly used in patients with nonspecific respiratory symptoms. In cases with only mild respiratory problems, the test does not improve patient outcomes, and it can lead to false positives. Often the test shows small lung nodules that can lead doctors to follow up with a high-risk surgical biopsy for cancer — which is very unlikely to be the cause of the symptoms. The scan also exposes patients to radiation, which is a risk in itself; studies have found that between 1.5 and 2 percent of all cancers in the United States are caused by radiation from CT scans.

To be fair, it is not surprising that doctors tend to overestimate the precision and accuracy of medical tests. The companies that provide tests work hard to promote their products. Doctors often think that ordering more tests will protect from lawsuits. Moreover, medical schools offer limited instruction on how to understand test results, which means many doctors are not equipped to do this well. Even when medical students have short classroom instruction in test interpretation, it is rarely taught in a clinic with actual patients.

There is no simple solution. One key step is . . .

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Written by LeisureGuy

5 October 2018 at 2:11 pm

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