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Guest Post on Controlling Medical Costs

My brother, Lee Evslin M.D., who is a pediatrician and who runs the Makai Ola Clinic on Kauai, wrote the email below in response to my post Medicare – The Promise That Can't Be Kept. He has a very different (and more qualified) point of views; so I asked if I could run this as a guest post. Of course, I'm reserving the last word for myself in a post to come.

Hi Tom,

Your blog on Medicare was interesting. Your line of reasoning though is an example of a concept you have spoken about since we were young.  You are looking at the problem through the same thinking that got us into trouble in the first place.  The problem will never be solved without a new way of dealing with ill health.  

Michael Pollan wrote an op ed article for the NY Times which does a fair job of describing one part of the problem. His article was about the "elephant in the room".

He is basically talking about the health care costs stemming directly from the food we eat. Health care in America is costing us 2.3 trillion dollars per year. This is twice what is paid on a per capita basis in Europe. For this staggering cost, we rank 37th among developed nations in health care outcomes. It is estimated that 75% of our health care costs are spent on chronic diseases.

Obesity is a major factor in causing cardiovascular disease and diabetes. Cancers of the prostate, colon and breast are also thought to at least partially be caused by our western diet. Obesity in America has almost tripled since 1987. Obesity (defined as a BMI over 30) has gone from about 13% of the population in 1987 to about 33% of the population in 2004 and an amazing 66% of the population are considered overweight. It is said that we are the fattest nation in the history of the world.

Bottom line is America's processed food industry is taking American government subsidies and producing food which has led to an epidemic of obesity and ill health. Chronic diseases are costing all of us 1.7 trillion dollars (75% of 2.3 trillion dollars).

Fix our food and we would go a long way to fix America's health care cost problem. Michael Pollan's point though is that this is not so easy. The processed food industry has enormous influence and even in Obama's crusade on health he was not able to take on the food industry at the same time as he went after the insurance companies.

The literature has numerous studies showing that everywhere the standard American diet goes, chronic diseases follow right behind. I have listed a few of the more commonly mentioned studies below:

In the 70s, a large study followed Japanese men and their diets as they moved from Japan to Hawaii and then to the west coast of the US. Heart disease rose with exact proportion to their adoption of the western diets.

BBC News reported recently that the British Journal of Psychiatry published data on 3500 government employees who were followed over five years. They found that those eating a diet "high in processed foods had a 58% higher risk of depression than those who ate very few processed foods."

They then subdivided those who were in the whole food group into two subgroups; those who ate mostly whole foods and  those who ate somewhat less whole foods.  Those eating the higher quantity of whole foods had 26% less depression than those who just ate somewhat less.

The Heart.Org reported recently on a study published in Lancet.  They presented the extended follow-up of a study known as The Diabetes Prevention Program (DPP).  The first results, published in 2002, showed that lifestyle change (diet, exercise, and weight loss) resulted in 58% less new cases of diabetes than in the placebo group. They also compared these results to patients put on metformin (a diabetes drug). The metformin group had only 31% fewer new cases of diabetes. In other words, life-style changes prevented diabetes almost twice as well as drug therapy and lifestyle changes also decreased the number of new-onset diabetics by almost 60% over those who did not change lifestyles.

The Archives of Internal Medicine reported on a German study which followed 23,153 adults ranging in age from 35-65 years. They were followed for 7.8 years. The four factors studied were:

Adherence to a diet which was high in fruits, vegetables and whole grain foods and low in meat consumption;

Never smoking;

Having a body mass index (BMI) less than 30 (A BMI of 30 and above is considered obese.);

Exercising 3.5 hours per week;

Those that followed all four positive lifestyles showed a dramatic decrease (78%) in the risk of developing one of four common chronic diseases. There was a 93% decrease in diabetes, an 81% decrease in heart attacks, a 50% decrease in strokes, and a 36% decrease in cancer. Can you imagine the profit and publicity from a drug that had the same preventative effects?

The diet described above, which is high in fruits, vegetables, and whole grain foods, and low in meat consumption, is the basis of the increasingly popular Mediterranean Diet. The Mediterranean Diet also includes nuts, legumes, olive oil, wine, and fermented dairy products such as yogurt and natural cheeses.

The Mediterranean Diet has proven beneficial in numerous studies. One Italian study showed that 50 of 90 people (56%) were cured of metabolic syndrome (high blood pressure, high blood sugar, and obesity) after 10 years on a Mediterranean Diet as opposed to only 12 of 90 people (13%) improving on a low fat diet. Other studies have shown the Mediterranean Diet to be associated with a decrease in abdominal fat, decreased risk of dementia in the elderly, decreased allergies in children and improvement in the health of the cells lining the blood vessels.

These studies speak well for themselves. The evidence is truly pouring in from around the world.  Processed foods and diets high in sugar and unhealthy fats are making us fat, plagued with chronic diseases and increasingly depressed. 

Bottom line:  The cost of medical care could be decreased dramatically if we stopped poisoning ourselves with our food and unfortunately "poison" is probably not too strong a word.

The food is one part.  The second part is quite complex but involves the industry of pharmaceutical and medical interventions that has grown around the fact that we have become unhealthy as a population by the food and lifestyles we have chosen or adopted.  First, we make ourselves really unhealthy and then we spend trillions treating the symptoms and not treating the underlying causes. There is an old analogy concerning treating a sink with a clogged drain by mopping the floor rather than by unclogging the drain or turning off the tap.  We will never solve the fact that our medical care will bankrupt the country until we fix our food and pay our medical care industry more money for reversing disease than we pay for applying really expensive bandaids.

Your Brother Bill

Medicare – The Promise That Can’t Be Kept

The promise was simple: once you reach 65, Medicare will assure that your medical costs don't become a catastrophic burden to you or children who might feel obliged to care for you. Since President Lyndon Johnson signed the Medicare bill in 1965 and gave exPresident Harry Truman the first enrollment card, the definition of "catastrophic burden" has been lowered many times by both Republicans and Democrats, the cost of medical care has skyrocketed as has the number of possible (usually expensive) medical interventions, and life expectancy has increased. The promise cannot be kept!

Geezers like me who recently reached 65 on the average had put in only on dollar for each three dollars of benefits we'll receive. That's a huge UNEARNED benefit. We didn't know that we'd be ripping off those still working but we are. The cap has been taken off earnings subject to Medicare tax; rich people pay a higher tax on their earnings than poor people. Premiums for recipients have been raised for those who are still classified as high earners. Payments to providers have been cut back forcing other users of health services to subsidize Medicare. But the funding gap keep growing inexorably as the number of workers supporting each retiree shrinks, we live longer and longer, and ever more ingenious (and expensive) medical procedures are invented. Raising taxes on the rich wouldn't solve the current problem let alone the future one; there's no one to pay for our care but us and our kids. Charging the kids more now means there's an even bigger gap when they retire. The promise cannot be kept!

The future of Medicare is a lousy campaign topic because there is no good answer. Politicians made us a promise they can't keep. We believed what we wanted to believe. And now there'll be a Medicare default plus an expensive Medicare bailout. There's no one to sue. We have to pay the piper both in terms of benefits we won't receive and money we'll have to pay.

Cutting benefits to current retirees is both unfair and absolutely necessary. We were promised our medical needs would be taken care of, so we didn't make any provision other than the Medicare tax we were paying. We didn't think we were getting something for nothing. We didn't have the chance to choose a different option. But we getting $3 of care for each $1 we paid. Our premiums can – and should – go up on a means-tested basis. Which procedures are covered should be more tightly restricted, although we should retain the option of paying for them ourselves if we or our heirs can. I'd like the option of opting out, self-insuring for routine stuff, and buying only catastrophic insurance. It may be, however, that giving me that option and forgoing my already higher premiums would make the problem even worse. Perhaps the more well-to-do ought to be able to buy themselves part way out. There is no answer that's fair to those already in the system or close to retirement. It's just a question of limiting the damage. The promise cannot be kept!

We can't keep the promise to today's workers that they can have medical care from 65 to the grave at almost no expense to them or their heirs. We need to tell them the truth and let them make some choices now. Private insurance can provide plans for retirement coverage – but it is hard to convince a twenty-something to forgo current expenditures to pay for those impossible to imagine days as a geezer. But young people do pay into retirement funds; they do (sometimes) save for their own kids' college. Under compulsion, they're paying for Medicare now; but we're spending every penny they're paying. I don't think it's a terrible injustice for those who have money but failed to buy insurance to have to sell their (or their heirs) assets in order to pay for the medical care they want. We spend our retirement funds on our other priorities. I would've sold my house to pay for my stent if I'd had to – or chosen a lifestyle that let me work around a damaged artery. What's essential is to present these options to current workers today so that they can still make a choice. We cannot make them promises that can't be kept!

I'm sure you've noticed that I haven't talked about what should happen to those who couldn't afford insurance and can't afford medical care. That's a different, although still critical, problem. The Medicare problem is a promise made to us who had alternatives, a promise there is no one to pay for except us, which turns out to be a promise that can't be kept. The sooner we recognize the default, the less the pain of curing it.

Related posts:

Rep. Ryan's Budget: Change You Can Believe In

Medicare's a Fraud – And I'm the Beneficiary

We Can't Have All the Medical Care We Want

Don’t Argue with 911

"What's the nature of your emergency," the 911 operator asked.

"My wife is having a possible heart attack," I said.

"What's your location?"

"I'm on 89 North. Just passed mile marker 72. I'm going to Fletcher Allen. Fast." I was going eighty, ninety when there was room. It was dark but the road was dry.

"Sir, can I convince you to stop so I can get help to you."

"No. Sorry. I can get her there faster if I keep going. But if you can have an emergency vehicle meet me, I'll stop and transfer her."

"Sir, an ambulance has equipment to treat her. Do you have that in your car?"

"No. But it'll take too long to wait for an ambulance. I'm at mile marker 74."

"Sir, can you get off at the Richmond exit? It's in five miles."

"Can you get an ambulance there before I get there?"

"The ambulance will be there very quickly once I call it. Sir, it would be better if you got off."

"Call the ambulance and ask them how long it'll take them. Maybe they should meet me at Williston."    

"Sir, I can't call them until you tell me where you're getting off."

Mary was barely conscious. She didn't even tell me what to do which meant she was very sick indeed.

"I'll get off at Richmond. Call the ambulance."

"Can you go the park and ride at Richmond?"

"Yes. CALL THE AMBULANCE."

The 911 operator stayed on the line. The Richmond fast squad arrived at the park and ride five minutes after we did. They stabilized her and got her to Fletcher Allen in better shape than I would have. Turned out she was having a severe reaction to a prescribed medicine and her heart is certified fine. Two days later she was being Mary again and going to emergencies as a Red Cross volunteer rather than being the emergency.

But don't be as dumb as me. The ambulance would've been in Richmond five minutes earlier if I hadn't wasted time arguing. Five minutes could've mattered more than I want to think. Good thing the 911 operator was patient and persuasive or I would've been even dumber.

 

Great Docs and Technology Saved My Life Thursday

"You flunked the stress test," was the essence of the call Tuesday morning. I'd thought I aced it. "Don't do anything you don't have to. We'll get you in to see a cardiologist ASAP."

"But I got through the whole test," I told the cardiologist that afternoon. "The EKG was normal; they were surprised that it took so long to get my pulse up but that's because I climb mountains and play tennis all the time." I was in denial, just as I've been when I got the first mild chest pains during warm up for racquetball last spring and played through them; just as I was when my chest tightened at the beginning of most spring climbs and I kept walking (but a little slower). My denial had faded some in early summer when I woke up twice with chest pain, took two Excedrin, and went back to sleep. But it was only a little pain; really just pressure on my sternum. And it stopped happening.

Because I time everything and my Garmin watch tracks my pulse, I knew I was climbing mountains more slowly and reaching lower maximum pulse levels even though the pain went away. I hiked alone so people wouldn't have to wait for me (Bruiser, my labradoodle, can always find something to sniff while he's waiting). It bothered me that I was losing at tennis, usually in the second and third set when it was an effort to get my arm up to serve. I tried jogging to get in better shape and couldn't quite run a mile on the flat. But I am 68, getting older, but… So I asked my doctor to make an EKG part of my upcoming physical.

"There's a slight abnormality," she said. "And you have a lousy family history. I think you should take a stress test." I really did think I aced the test. I felt good. I could see the inside of my heart on the echocardiogram and it even had cool Doppler, which used color coding to show the velocity of blood and tissue in both directions. It looked like there was a cheerful little guy standing in the middle of my heart waving his arms up and down (the valves) and cheering me on "Yay, Tom. Yay, Tom." They took video of the heart at rest; then the treadmill up to 142 pulse; then more pictures so they could compare the stressed heart to the resting one.

"Much of the muscle wall of your left ventricle is not participating in the pumping after stress," the cardiologist said. "The test has only about 10% false positives. The most likely cause is a blockage in one or more arteries. You could die suddenly from that condition, most likely from a piece of plaque breaking off and corking something crucial. You should have an angioscopic examination to find where the blockages are." That means, in case you don't know, that a catheter is threaded through your groin or wrist artery into the arteries which supply the muscles of the heart. It injects die, which makes the blood flow show up clearly on a monitor.

"And then what," I asked?

"If the blockage is not too widespread, they'll put in a stent immediately as part of the same operation while the catheter is still in place."

"I've heard about stents," I said; "aren't they overused?"

"They're not overused here in New England," said the doctor. "The financial incentives are different and we tend to be very conservative in the use of stents." He explained that the most statistically significant trial of stents vs. medication alone vs. bypass surgery is somewhat inconclusive. The long term survival rate was about the same with either medicine alone or stents plus medicine. However, in the first three years, quality of life is better with stents because the blockage is immediately dealt with. Long term results are about the same for bypass surgery as stents for relatively simple cases and better with surgery for complex cases. Stents do sometimes have to be redone. There is, of course, more mortality associated with the bypass operation itself and recovery is lengthy and painful (as I know from friends and my father). One reason why results from all three approaches tend to converge over time is that people develop new blockages at new sites after the first blockages are cured – either because they haven't changed their lifestyle or because they can't change their genes.

Since the big trials were done, a second generation of drug-eluting stents has been developed which should be better than either uncoated stents or those coated with the first generation of medicine; so quite possible the next big trial will show significantly better outcomes for stents than either medicine alone or bypasses when there is an option to use stents instead of bypasses. The drugs discourage the body from growing new plaque inside the stent but do increase the risk of clotting. To counteract that risk, you take blood thinners for a year.

I checked all that on the web with the help of my brother Lee, who is a pediatrician with a strong interest in and knowledge of overall health. And I scheduled a second opinion just before the angiogram was scheduled to begin Thursday. I had no doubt I wanted the diagnostic information from the angiogram; I was skeptical I wanted to go right into having a stent inserted and knew, although I'd be awake through the operation and when we learned what the angiogram showed, I'd be much too dopey to give informed consent to anything at that stage.

"The EKG was normal," I said. I'm now back in denial. The report even says that my "functional capacity was above normal. I don't do anything with good form; maybe my heart doesn't either. You've already explained to me that it's normal to find some blockage in almost everyone, even children. How will we know I really need a stent? Maybe there isn't any serious blockage."

"There's a 99% chance, in my opinion, that you have a serious blockage – by which I mean a blockage of over 70% - in at least one artery," the cardiologist explained. "If there's no blockage above that level, we'll do nothing and have to reconsider what's causing the symptoms. If there are one or more blockages above 70%, if there aren't too many and they aren't too complex, we'd like to stent immediately. If it's worse than that, we'll stop and can consider options later with the new information we have. You wouldn't want the surgeon to put in stents if he doesn't think they'll work, would you?" He also told me, politely, that I'm not more qualified to determine whether I need stents than cardiologists are.

"OK," I said begrudgingly. "Numbers I can live with. Less than 70%, no stent. Too complicated, we put off the decision. Over 70% and relatively simple, stents away. But, if the decision is on the cusp, two things I know that the surgeon needs to know: I will stick with any post-op regime and I'd gladly take some risk to be able to stay active." We had a deal. Time to get prepped for the operation.

The surgeon was ready so two nurses prepped me fast and efficiently. IV already in, I said good-by to Mary (we were both scared) and was wheeled to the operating room on a gurney. The surgeon threaded the catheter in through my right wrist and guided it to the arteries serving my heart; I'm not quite sure how. I'd hoped to watch the catheter on the TV screen next to the operating table – maybe I did – but the sedative you get for this operation makes you forgetful even though you can respond to requests to move this way or that. I do remember him saying that they'd found 98% blockage in a major artery and showing me that on the screen. I could see that the thick flow of blood simply stopped at one point and became a tiny stream. "Can you stent it?" I remember asking.

A balloon is threaded over the catheter and the stent is paced over the balloon. The balloon is inflated in the blockage and compresses the plaque back to the artery walls (angioplasty); the same inflation expands the stent so it stops the walls from rebounding. Catheter removed from the tiny hole in my wrist. "It's done," he said some time later. "Do you want to go home tonight?"

The surgeon went off to talk to Mary and show her the video. Soon she rejoined me in recovery; I was out of the hospital at 6PM; amazingly just five hours after the operation began. In a week I can resume full activity and will, quite possibly, hike faster and win at tennis.

I was really stupid to ignore the first symptoms, especially to try to walk them off by hiking alone (please don't do the same). I am lucky to live in a time when techniques like echocardiography exist. The previous stress test I took relied on EKG only – and showed no problem. The EKG showed no problem this time; it only showed up on echocardiogram. I was also lucky to be treated by an amazingly skilled and compassionate team associated with Fletcher Allen Health Care. We're very well-served having them here in Vermont.

DIY Medical Records in the Cloud

Burlington Prosthodontist Dr. Bentley Merrick made me teeth much better than the ones I'd grown on my own. At the end of the two-and-a-half year process, he emailed me a set of x-rays and pictures showing how the whole structure is put together and the special tools he made to screw teeth into abutments which screw into implants. "I know you travel a lot," he said; "hopefully nothing'll go wrong; but, if it does, whomever you see for treatment will know what to do."

"Cool", I said, although I didn't like the thought of anything going wrong.

I put the all the files into a folder on my computer so that they'll be available when I need them. Then I thought about the time my computer was stolen... and realized that's not a problem.

My files are backed up nightly by a service called Mozy and go somewhere into a cloud. I can retrieve the files from any computer anywhere; I don't need my computer, just my password. Even better, Mozy has file-retrieval apps for both my droid and Mary's iPhone; we don't even need a computer to find out how to reassemble my mouth if the need arises.

Of course all medical records ought to be available online but they're not. Now that I know how to put my records where I can get them if I need them, I intend to ask my doctor and anyone else who treats me for full records. Whenever I get anything new, I'll simply put it in a folder with a reasonably descriptive name including a date and know that it'll go to the cloud with that evening's backup and available either on my computer or from any PC or phone with a data connection. Should've thought of it before.

Related posts:

Blog Blocked by Breakin

 

File Recovery Postscript – Do You Know Where Your Files Are?

WHO Doesn’t Like the Gates Foundation

From a recent article in the New York Times:

“The chief of malaria for the World Health Organization has complained that the growing dominance of malaria research by the Bill and Melinda Gates Foundation risks stifling a diversity of views among scientists and wiping out the world health agency’s policy-making function.

“In a memorandum, the malaria chief, Dr. Arata Kochi, complained to his boss, Dr. Margaret Chan, the director general of the W.H.O., that the foundation’s money, while crucial, could have ‘far-reaching, largely unintended consequences.’”

WHO is a UN organization, in case you didn’t know. UN agencies, even those that don’t do their job very well (most of them), don’t like to have their “policy-making function” wiped out.

Dr. Kochi, according to the NY Times article from which all facts following in this post come,  says the Gates Foundation is forcing recipient scientists into “group think”. A Dr. Amir Attaran at the University of Ottawa agrees with Dr. Kochi but “…believed that scientists were not afraid of the foundation, but of its chief of malaria, Dr. Regina Rabinovich, whom he described as ‘autocratic.’”

The Gates Foundation has spent about $1.2 billion on malaria research. Before their involvement in 2000, less than $100 million a year was being spent on this and drug companies had pretty much abandoned the field. You’d think the Foundation would be entitled to have an opinion and influence policy since it pays the bills but not according to Dr. Kochi who complains that the foundation “even takes its vested interest to seeing the data it helped generate taken to policy.”

I had a lot of contact with Bill Gates and Melinda and I were peers when I worked at Microsoft. I’d much rather have them setting policy – particularly on how their money is spent - than UN bureaucrats. Yeah, Bill can be arrogant; yeah, people who work for him sometimes think aping the arrogance will also make them as brilliant and successful as them. But, when Bill gets “hard core” about things, they get done. The things the Gates Foundation is doing need someone getting hard core about them. They need much more rigorous analysis and much better execution than the UN especially but also many other governmental and non-governmental have shown themselves capable of.

The last few paragraphs of the Times story may well explain what the Gates Foundation has done to raise the ire of UN officials:

“There have been hints in recent months that the World Health Organization feels threatened by the growing power of the Gates Foundation. Some scientists have said privately that it is ‘creating its own W.H.O.’

“One oft-cited example is its $105 million grant to create the Institute for Health Metrics and Evaluation at the University of Washington. Its mission is to judge, for example, which treatments work or to rank countries’ health systems.

“These are core W.H.O. tasks, but the institute’s new director, Dr. Christopher J. L. Murray, formerly a health organization official, said a new path was needed because the United Nations agency came under pressure from member countries. His said his institute would be independent of that.”

Maybe we ought to find out what other UN functions the Gates Foundation would be willing to take over.

Answers to Probability Puzzle

As usual, smart readers knocked the cover off the ball almost immediately. Some day I’ll stump you.

First question taken from Randomness by Deborah J Bennett:

“If a test to detect a disease whose prevalence is one in a thousand has a false positive rate of 5%, what is the chance that a person found to have a positive result actually has the disease, assuming you know nothing about the person’s symptoms or signs?”

First to answer correctly was Matt Crawford:

“Assume that the test is performed on everyone regardless of symptoms of the disease. Then out of every thousand people who receive the test, one has the disease and 999 do not. Further, assume that the test has no false negatives: anyone who actually has the disease gets a positive result. Then 1 out of every thousand tests are true positives. The remaining 999 should be negative results, but the 5% false positive rate means that 49.95 (so round to 50) of these people will receive false positive results. Then out of our 1000 tests, 51 return positive results. But only one of these is a true positive, so the chance that a positive test identified someone who actually has the disease is 1/51 or about 2%.”

You might quibble that 5% false positives means 50 false positive out of a population of 1000 (plus one correct positive) but this is close enough. It’s fair to make the assumption that there are no false negatives since this isn’t stated in the question (and otherwise you’d be unable to answer) but Aswath is right to point out this should have been specified.

Second question: “what percentage of the physicians, residents, and fourth year medical students at a prominent medical school who were asked this question got it right?”

jb guessed that 80% of those tested would give the tempting wrong answer of 95%. Actually, only 19% gave the right answer but only 50% said 95%. jb, you would’ve nailed it if you hadn’t given more detail in your answer than called for. Rob’s an optimist and hoped that 80% would get it right because their care is so important and getting into medical school requires critical thinking. He’s dead right that it’s scary that so many get it wrong.

Interesting answers to third question: “why is it critically important that doctors be able to get this one right? Give one example.” Most not about doctors, though. This type of bad thinking does cover lots of ground.

Matt Crawford cites the Red Cross using an HIV test on donated blood which is known to have a high incidence of false positives and speculates that many donors are probably panicked by the result. “However, the Red Cross continues to use the same test, probably because it combines low cost with very low false negative rate. In this case it may be justified to trade a high false positive rate for a low false negative rate, because a false positive merely requires a second test but a false negative would spread HIV through transfusions.”

Curtis Carmack says: “the medical profession as a whole has given insufficient thought to how to address the false positive issue with patients, leading to much more angst than is necessary when patients receive a positive test result -- invariably late on Friday -- and have to wait at least a couple of days to ask questions about it. ;-)”

Dennis Shanley posts: “This directly effects the overall cost of health care in a huge way. Assume that it costs $10,000 to cure a patient who presents positive. Not an unlikely assumption. Assume further that the 50 false positive patients do not exhibit negative effects as a result of their treatment that require further medical treatment and they do not litigate as a result of the unnecessary treatment. This is a highly improbable assumption made for the sake of simplicity.

“The true cost to cure 1 patient is $10,000.

“The cost to cure that one patient and treat the 50 false positives is $510,000.”

Aswath writes: “Suppose now we are told that the false positive predominantly affects a biological group - gender or a racial group. Will that decision stand reason? Let us assume that the situation is internment during WWII in US. A nation has to live with the effects of a callous operation decision to accept a large false positive.”

Otmar: “There is another interesting application for this kind of statistics: The beloved war on terror. The chance of a random person to be a terrorist is hopefully less than 1/1000. Imagine you manage to build some automated system which somehow claims to spot suspicious behavior, known faces, or miscreants by some other clever scheme.

These systems all have a non-negligible error-rate. If you're really lucky, you might push that one down to less than 1%.

“Now do the math again, assuming a 1/100000 terrorist-rate and 1% false positives. No wonder I read that one trial for such a system got terminated.”

The point is that you must weight the costs of being right and the costs of being wrong both for the positive and the negative case. Back to medicine, suppose your doctor is one of the benighted 81%. He or she tests you using the test in the first question and you come up positive. Let’s suppose that the disease is always fatal if not treated and there’s a treatment available but it has a 25% chance of killing you itself. If the doctor believes that there’s a 95% chance you have the disease, the dangerous treatment is clearly justified; but, since the true likelihood is less than 2%, the treatment is more dangerous than your untreated prognosis. Always a good idea to get a second opinion AND check your doctor’s math.

A Probability Puzzle

From Randomness by Deborah J Bennett:

“If a test to detect a disease whose prevalence is one in a thousand has a false positive rate of 5%, what is the chance that a person found to have a positive result actually has the disease, assuming you know nothing about the person’s symptoms or signs?”

For extra credit: what percentage of the physicians, residents, and fourth year medical students at a prominent medical school who were asked this question got it right?

Extra, extra credit: why is it critically important that doctors be able to get this one right? Give one example.

This is an honor system non-open book test.

Answers in comments, please. Will highlight correct answers in a subsequent post. Hat tip to Nassim Taleb in Fooled by Randomness for citing Bennett’s test.

Answers here.

Livestrong

The post below was written by my nephew Cody Clinton, a second year medical student. The "grandmother" he writes about is my mother who, for the last twenty plus years has bravely battled the horrors of Parkinsons and the side effects of the medicines which slow but don't stop its progression.

************************

LIVESTRONG

What does this word mean to you? Is it about living healthy, exercising, and studying hard? Most medical students would probably agree. Could it be a state of mind; a belief system affirming you will not accept what others tell you will inevitably occur? For a lot of cancer survivors, this may have been a mantra that kept them alive. But could it be the exact opposite? Could it be accepting what others tell you about your road ahead, even when you know it scares the hell out of you? Ask a terminally ill patient. My guess is that they relate better to this last admission, are prepared to end their life, and may even feel more at peace about their situation than you do. For a family member, this is a tough pill to swallow.

So, what is the true meaning of livestrong? This was a question I asked myself over the last few weeks. I experienced all of these different scenarios above, albeit some vicariously, and still struggled with the answer. The problem being, that each group of people was absolutely committed to their own ideals. They were convinced that they were right and were not about to change their minds, in spite of the best advice of those around them. Never had I seen more determined individuals in all of my life. Unfortunately, it took 24 years to see it. Fortunately, it took getting my head out of the books and grasping the opportunity to experience real medicine for the first time since I entered medical school.

It all began on August 26th, when students at our college provided medical support for bike riders taking part in a 100 mile Livestrong Challenge. First, let me preface by saying that a 100-mile bike race in extremely hot conditions, on a hilly course is not easy. It is a grueling test of your endurance, muscle strength, and mental composure. In short, it is downright masochistic. I do not recommend it. Yet these riders were out in full force. The riders were largely composed of cancer survivors, as well as family members, friends, and loved ones of cancer victims. There was even one female rider who flew in from Chicago and completed the entire course while in the middle of a chemotherapy regimen! It was absolutely jaw dropping. A member of our medical team, who had recently battled Non-Hodgkin’s lymphoma, described this rider as “ needing to finish the race, in order to keep her mind off the reality and gravity of her own situation.” By the way, this medical student waited at the finish line, even while the race was over, and made sure that her newly found friend made it to the end.

Over the course of the day, we witnessed riders speeding down flats and attacking hills, completely by themselves. Yet, you could feel that deep down they were back on the pavement with their old friends or loved ones, rehashing past experiences. It is a very difficult scenario to have to imagine and an extremely sobering sight to see. It meant much more that simply finishing a long bike ride, instead signifying a step closer to maybe finding some closure to a situation that they were not ready to face. You could see in all of the riders’ faces that living strong was much more than just a physical challenge, but an emotional challenge one as well.

The next unexpected development occurred shortly thereafter, on a morning when the only decision I was planning on making was whether I wanted hazelnut or regular coffee to get me through the morning. I received a call from my family notifying me that my grandmother was in septic shock and might not make it through the day. I immediately rushed up to the hospital where she was being treated, not knowing whether I would be staring at a blank corpse or my last remaining grandparent. Thankfully, she was still alive, was being stabilized, and had a good prognosis. Yet, even stable, she was suffering from Parkinson’s disease, congestive heart failure, a collapsed lung, immobility, and blindness. I wanted to do everything in my power to get her better as quick as possible and back into her home where we could take care of her. But this was not what she wanted. What she desired, and had told my mother repeatedly, was not to be resurrected every time she fell ill, but rather left to let “nature take its course” and die in her own home. I wasn’t ready to hear this kind of news. After some tough reflective time, it soon became clear that the choice my grandmother had made was completely justified because it was what she wanted, not what the people around her felt was best.

Witnessing these difficult decisions gets me thinking about what the term livestrong means for patients that are nearing the end of their lives. For them, living strong is about being confident in their choice to die. Terminally ill patients, unlike the riders and cancer patients, do not find strength from rage or unresolved opportunities. They take solace knowing that they have fought hard, and hopefully will find a place that rids them of their suffering and rewards them for their sacrifices. For them, livestrong is about resolution.

The truth is, as I am sure you know, is that the meaning of this word conjures a different ideology for each person and likely will vary throughout his or her life.  Gratefully, we are all distinct. Yet, we all share a similar passion. Health professionals, cancer survivors, and hospice patients alike, we all want to be content with our actions and decisions throughout our lives. It doesn’t matter if these decisions might not be the most sensible, or if we are going “against the norm”. As long as in the end, we have weighed all our options and trusted our own instincts, can we can go to sleep soundly. Only then, will the word livestrong hold meaning.

Treatment monitoring and thermometry for therapeutic focused ultrasound

If the title above doesn’t sound like it belongs on Fractals of Change, that’s because it’s from a paper co-authored by son-in-law Hugh Morris which has just been published by the International Journal of Hyperthermia. Last year I blogged about the research Hugh is doing in London on using ultrasound for non-invasive surgery. This paper is an outgrowth of that research.

The technique they’re using to zap cancers is an interesting one: a number of high-frequency sound waves are beamed into the body.  None of the waves by itself has enough energy to do any damage as it passes through skin and other tissue. Aimed right, the beams converge at the site of malignity.  When focused, the beams together have enough energy to heat up bad cells and cause them to die.

The problem Hugh has been working on is how to measure the actual temperature being produced so that treatment can be best calibrated to kill all the bad cells with minimal damage to surrounding tissue. Sticking a thermometer into the patient is one option but this is invasive and also can interfere with the treatment since the thermometer itself may scatter or affect the beams and interaction between the beams and the probe may actually change the temperature you’re trying to monitor.

So it would be better to use MRI or some other non-invasive technique to measure temperature indirectly.  In fact, ultrasound itself can be used to measure the temperature by reporting on tissue changes. But how do you know what MRI or ultrasound reading corresponds to what temperature? How do you know which temperatures are most effective in the first place if you don’t know what temperature you’re operating at?

Hugh has been working on using probes in bovine liver (he buys the livers without the cows) to measure temperature induced and calibrate that with the readings given by non-invasive techniques. The problem he’s had to contend with are that the probes do affect the temperature being measured.  You could correct for that if you only knew how much effect is induced over how much time.

In case you didn’t guess the solution: “Morris et al. proposed a refinement to this [earlier] technique. Instead of assuming an arbitrary time for the end of the first phase [of induced heating] , the time was chosen from analysis of the second differential of the temperature with respect to time…. Morris et al. have also used thin-film thermocouples as a viscous-free reference, and calculated the viscous effect for a wire thermocouple as a function of time by subtracting the TFT measurement from the wire measurement.” Makes sense to me (not really).

What I do understand (because we saw it) is the dedication of young scientists constructing experiments, failing, correcting, trying again, avoiding false positives, questioning, retesting, and (sometimes) coming up with something very exciting.

We’re proud of Hugh.

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