There has been much written lately about the utility or non-utility of the annual physical exam and its associated tests. There have been articles in the New York Times, the Annals of Internal Medicine and the Journal of the American Medical Association, as well as statements by the National Institutes of Health, the American College of Physicians, the American Academy for Family Practice the Canadian Medical Society, and various other organizations. Since there has never been an overall consensus, the reading public is left confused and thrown back on its own resources and preconceptions.
Firstly, what do we mean when we say that an annual physical exam is "beneficial" to the patient? The answer to that question depends in part on who we ask, and in part on how we measure "beneficiality". Do we ask the opinion of the patient, the doctor, a medical organization, a patient organization, an insurance company, or the government? Is an annual physical exam and its associated tests beneficial if it saves the patient's life, or if it reduces future morbidity, or if as a result the patient functions with more physical and/or mental energy? And what of the sense of well-being that a patient feels when he/she is told that the results of the annual exam were perfectly normal? Do we discount that feeling because there is no way to measure and quantify it? Isn't there value in reassuring a patient that his/her aches and pains are not the symptoms of a serious disease? What if the meat of the annual exam lay in one question that the physician answered for the patient, or one medical misconception that the doctor cleared up and thereby enabled the patient to avoid a future medical problem?
In previous blogs I have listed questions that should be asked at the annual physical, and which tests I think are medically beneficial and which are not, along with my reasons for the tests. One could make a case that just making sure that the patient received an annual flu shot is enough reason for an annual physical. One could also make a case for measuring blood pressure, since there is plenty of clinical evidence that treating hypertension with a regime that includes a diuretic reduces the patient's risk of a cerebral stroke. There is also an argument for annual testing for infectious diseases that can be treated, such as tuberculosis, syphilis and AIDS. What of the benefit to society when I ask a patient if he/she has trouble reading street signs at night while driving, and then suggest seeing an ophthalmologist if the answer is "yes"? I gloss over the obvious comments a physician would make to the patient about losing weight, stopping smoking and getting more exercise (although a recent study showed that 10% of the patients who exercise damage their health by doing so, two studies published in Lancet showed that overweight people with a BMI between 26 and 29 had better odds of surviving a heart attack, and two European studies demonstrated that smokers have a reduced incidence of Parkinson's disease). And should I encourage teetotalers to have a daily glass of wine since every study shows that this nutritional intervention improves mortality?
One fact that is never mentioned in all the discussions of annual physicals is state law: in every state it is a violation of "good medical practice" for a doctor to renew a prescription if the patient has not been seen within the previous 12 months (and more frequently for DEA-controlled drugs, which includes sleeping pills and tranquilizers). By age 40 almost every patient is taking at least one prescription drug, and therefore needs to be seen annually. And for those only taking over-the-counter supplements, their regime should also be reviewed annually to keep them from consuming OTC drugs that might be harmful----e.g. we now know that daily doses of Vitamin E increases your risk for having a heart attack.
Friday, June 8, 2012
Thursday, May 17, 2012
How Can We Help Our Patients to Stay Healthy?
The previous blog was written somewhat tongue-in-cheek, but a judicious application of financial rewards and penalties would undoubtedly work to make patients give up unhealthy habits and take up healthy ones. Just think how the percentage of drivers who used seatbelts increased once tickets were issued for being unbuckled. In the same vein, if the penalty for jaywalking were a $1,000 fine, we would certainly see less jaywalking and, pari passu, fewer pedestrian deaths. In Arizona motorcyclists wear helmets, but in Utah, where there is no such law, most "donorcycle" riders do not. So how can doctors reach patients, to educate them and to change their habits, bearing in mind that most patients with unhealthy habits (e.g. smoking) know that the cigarette habit mitigates against a long or a healthy life, and will further cause them to be a burden to their loved ones and their relatives?
I have long been convinced that our human brain is geared to avoid immediate (in the next 10 seconds) threats rather than time-distant threats. Hence "a bird in the hand is worth two in the bush", but "a stitch in time saves nine" is less frequently quoted. No one thinks that cigarettes are good for you. Even before the current studies directly linking cigarette smoking to an increased risk of heart disease, chronic emphysema and lung cancer we called them "coffin nails". But no cigarette smoker thinks that the cigarette that he or she is smoking right now will kill them, and that is precisely the problem.
In a similar vein, no overweight patient fails to notice the increase in weight, or thinks that that overweight is healthy. I have repeatedly told my overweight diabetic patients that they could cure their diabetes or at least diminish the amount of medicine they take by losing weight, but to no avail. Why doesn't the average human, after noticing an increase in belt or dress size go on an immediate diet? The majority of dedicated dieters in my practice are men after their first heart attack, which is really locking the barn door after the first horse has left.
If there is an immediate reaction to improper eating, then of course patients are careful. So patients with a peanut allergy, or lactose intolerance or celiac disease (gluten sensitivity) are very careful eaters. But even with the posting of the amount of calories in a given serving (this study was done in Taco Bell in Los Angeles) patients do not decrease the total amount of calories they eat. Why?
When patients measure their blood pressure or blood sugar at home, they usually repeat the measurement several times to get a "good" number to show the doctor. Many patients swear that they eat nothing and can't understand their failure to lose weight, but when I ask them to write down everything they eat in a daily diary and then tally up the calories for them, they are invariable surprised. Maybe that is why the only proven method of sustained weight loss is surgical: stomach bypass surgery or stomach banding.
Whenever I poll my medical residents, more than half of them stopped taking their antibiotic prescription before the bottle was empty. One study showed that 25% of patients who leave the doctor's office with a prescription never fill it, and of those who do dill it, 25% place the bottle in a drawer and never even take the first pill. The majority of patients believe that the more medicine they take, the sicker they are, so they try to taper or omit their doses of medicine, a habit that can have tragic results in an asthmatic or a hypertensive patient. What I am driving at is that it is not the lack of patient's disease knowledge or lack of patient education by the physician that is the problem, nor is it a lack of government guidelines. Rather, people just don't seem to think that the medical advice applies to them, or that failure to follow their doctors' advice will have negative consequences.
We all have had patients who have suddenly decided to give up smoking, or to lose weight, or to exercise, and we can certainly help them in this task. But no one, not even even the patients themselves, knows what made them "throw the switch" and adopt a healthier life style. This is the real problem facing public health: how to motivate the population to act in healthier ways, and neither blaming the patient population for being ill-informed nor simply telling to give up unhealthy habits seems to be the answer.
I have long been convinced that our human brain is geared to avoid immediate (in the next 10 seconds) threats rather than time-distant threats. Hence "a bird in the hand is worth two in the bush", but "a stitch in time saves nine" is less frequently quoted. No one thinks that cigarettes are good for you. Even before the current studies directly linking cigarette smoking to an increased risk of heart disease, chronic emphysema and lung cancer we called them "coffin nails". But no cigarette smoker thinks that the cigarette that he or she is smoking right now will kill them, and that is precisely the problem.
In a similar vein, no overweight patient fails to notice the increase in weight, or thinks that that overweight is healthy. I have repeatedly told my overweight diabetic patients that they could cure their diabetes or at least diminish the amount of medicine they take by losing weight, but to no avail. Why doesn't the average human, after noticing an increase in belt or dress size go on an immediate diet? The majority of dedicated dieters in my practice are men after their first heart attack, which is really locking the barn door after the first horse has left.
If there is an immediate reaction to improper eating, then of course patients are careful. So patients with a peanut allergy, or lactose intolerance or celiac disease (gluten sensitivity) are very careful eaters. But even with the posting of the amount of calories in a given serving (this study was done in Taco Bell in Los Angeles) patients do not decrease the total amount of calories they eat. Why?
When patients measure their blood pressure or blood sugar at home, they usually repeat the measurement several times to get a "good" number to show the doctor. Many patients swear that they eat nothing and can't understand their failure to lose weight, but when I ask them to write down everything they eat in a daily diary and then tally up the calories for them, they are invariable surprised. Maybe that is why the only proven method of sustained weight loss is surgical: stomach bypass surgery or stomach banding.
Whenever I poll my medical residents, more than half of them stopped taking their antibiotic prescription before the bottle was empty. One study showed that 25% of patients who leave the doctor's office with a prescription never fill it, and of those who do dill it, 25% place the bottle in a drawer and never even take the first pill. The majority of patients believe that the more medicine they take, the sicker they are, so they try to taper or omit their doses of medicine, a habit that can have tragic results in an asthmatic or a hypertensive patient. What I am driving at is that it is not the lack of patient's disease knowledge or lack of patient education by the physician that is the problem, nor is it a lack of government guidelines. Rather, people just don't seem to think that the medical advice applies to them, or that failure to follow their doctors' advice will have negative consequences.
We all have had patients who have suddenly decided to give up smoking, or to lose weight, or to exercise, and we can certainly help them in this task. But no one, not even even the patients themselves, knows what made them "throw the switch" and adopt a healthier life style. This is the real problem facing public health: how to motivate the population to act in healthier ways, and neither blaming the patient population for being ill-informed nor simply telling to give up unhealthy habits seems to be the answer.
Monday, May 7, 2012
How to Improve Medical Care (and Save Money)
I have been reading many articles recently about this plan and that plan to improve the medical care of patients, to reduce medical expenditures, and generally to make us a healthier society. All of these different suggestions have one point in common: they neglect basic human psychology. In what follows I list several interventions and modifications that should help all of us reach these lofty goals. And like any CEO, I am setting forth goals and techniques and leaving it to others to work out the nuts and bolts of implementation.
It has been said many times that man is an economic animal, at least on an individual basis (so I am here neglecting mob psychology). A universal method that improves performance is the reward method and for humans, unlike Pavlov's dogs, the most successful reward has been money. There have also been several test programs, usually in inner schools with students who are less than interested in their schoolwork: when these students received a financial reward for not being late, or not being absent or doing all of their homework, their school habits improved. I would add the obvious statement that jockeys and college and amateur wrestlers and boxers all seem to be able to keep their weight down, and in their cases the rewards are immense. Similarly, most runway models manage to remain ultra-slim, as do the majority of movie stars and stage actors.
OTOH your brain is remarkable in its ability to maintain your weight by a continuous process of homeostasis. If we start to gain weight, our metabolic rate increases, in the brain's attempt to return us to where we were. Similarly, if we start to lose weight, the body's metabolism is slowed down by the brain, for the same reason. In addition, our metabolism slows by the equivalent of 3 to 5 pounds per year, so each year it becomes more difficult to lose weight (until about age 75 or 80). To realize how remarkably the brain does its job, consider that burning one pound of fat releases 3500 calories of energy. Thus if you ate an extra 3500 calories in one year, you would gain one pound. This works out to micromanaging your caloric intake to within TEN calories per day, a feat that even Superman would be unable to do. So the brain is always on the job, micromanaging our metabolism to keep our weight as constant as possible.
The Motz proposal for better health simply involves offering financial awards for achieving certain benchmarks. It makes much more sense to reward the patients, who are the direct agents, than to reward the doctors in a Pay-4-Performance program for what their patients do. We could award (possibly by income tax credit) patients who lost ten pounds in a year, or who had annual pap tests or mammograms, or had their blood pressure or cholesterol measured in the previous year. Then goals could be set, with an annual reward for achieving and maintaining a certain weight, or blood pressure, or average sugar.
There are of course many details to be worked out and considered: should doctors also be rewarded? how and where is the weight and weight loss and annual blood pressure etc. measured and certified? Perhaps we could start a trial pilot program in a county with a low population since it would be easier to track behaviors. We would all lose 10 pounds for a reward of $1,000,000, but not for a reward of $0.01. The question then becomes: how much would they have to pay you for you to lose and keep off 10 pounds in the next year? And should these successful patients also get a medal, or ribbon, or have their names posted in the newspapers?
I am certain that if we paid cigarette smokers $1,000/year to quit we would save much more than 60 x $1K = $60,000 in the future medical fees that would be caused by his/her continuing to smoke.
It has been said many times that man is an economic animal, at least on an individual basis (so I am here neglecting mob psychology). A universal method that improves performance is the reward method and for humans, unlike Pavlov's dogs, the most successful reward has been money. There have also been several test programs, usually in inner schools with students who are less than interested in their schoolwork: when these students received a financial reward for not being late, or not being absent or doing all of their homework, their school habits improved. I would add the obvious statement that jockeys and college and amateur wrestlers and boxers all seem to be able to keep their weight down, and in their cases the rewards are immense. Similarly, most runway models manage to remain ultra-slim, as do the majority of movie stars and stage actors.
OTOH your brain is remarkable in its ability to maintain your weight by a continuous process of homeostasis. If we start to gain weight, our metabolic rate increases, in the brain's attempt to return us to where we were. Similarly, if we start to lose weight, the body's metabolism is slowed down by the brain, for the same reason. In addition, our metabolism slows by the equivalent of 3 to 5 pounds per year, so each year it becomes more difficult to lose weight (until about age 75 or 80). To realize how remarkably the brain does its job, consider that burning one pound of fat releases 3500 calories of energy. Thus if you ate an extra 3500 calories in one year, you would gain one pound. This works out to micromanaging your caloric intake to within TEN calories per day, a feat that even Superman would be unable to do. So the brain is always on the job, micromanaging our metabolism to keep our weight as constant as possible.
The Motz proposal for better health simply involves offering financial awards for achieving certain benchmarks. It makes much more sense to reward the patients, who are the direct agents, than to reward the doctors in a Pay-4-Performance program for what their patients do. We could award (possibly by income tax credit) patients who lost ten pounds in a year, or who had annual pap tests or mammograms, or had their blood pressure or cholesterol measured in the previous year. Then goals could be set, with an annual reward for achieving and maintaining a certain weight, or blood pressure, or average sugar.
There are of course many details to be worked out and considered: should doctors also be rewarded? how and where is the weight and weight loss and annual blood pressure etc. measured and certified? Perhaps we could start a trial pilot program in a county with a low population since it would be easier to track behaviors. We would all lose 10 pounds for a reward of $1,000,000, but not for a reward of $0.01. The question then becomes: how much would they have to pay you for you to lose and keep off 10 pounds in the next year? And should these successful patients also get a medal, or ribbon, or have their names posted in the newspapers?
I am certain that if we paid cigarette smokers $1,000/year to quit we would save much more than 60 x $1K = $60,000 in the future medical fees that would be caused by his/her continuing to smoke.
Tuesday, May 1, 2012
Irritable Bowel Syndrome
Everyone has had irritable bowel syndrome at one time or another. Your entire digestive system from the rear of your mouth (actually the lower two-thirds of your esophagus) to the top of your rectum is under autonomic control. By that I mean that you have absolutely no voluntary control over the rate of progress of food through your digestive tract. All the muscles involved are smooth muscle, and are controlled by a complicated interaction between your sympathetic and parasympathetic nervous systems as well as a host of secretory hormones. There is also a constant interplay between the spinal nerves and the muscles and digestive enzymes of the gut, with modifications superimposed by the vagus nerve from the brain and the secretion of adrenalin.
We all have heard the expressions, and many of us have felt the sensation of "made me sick to my stomach", "made me throw up", "turned my stomach" "gave me agida or heartburn", "left a sour taste in my mouth", "my mouth turned dry", or "my mouth watered" , and thus are aware of the mind-body connection between our brain and our gut. The validity of these expressions was verified beginning in April, 1822. A French trapper, Alexis St. Martin, was accidentally shot in the stomach on Mackinac Island, Michigan, and healed by a Dr. William Beaumont. The healing left a hole directly into his stomach through the abdominal wall. Dr. Beaumont performed many experiments which he documented, including observing the color of the interior of the stomach wall, and the rate of digestion of a piece of meat dangled on a string into the stomach through the hole. He observed that when the patient got angry or upset, the stomach wall blanched indication a decreased blood supply, and the stomach muscles either stopped squeezing back and forth, or went into spasm. Under normal conditions, the stomach wall was pink. When he lowered a piece of meat into the stomach, the walls became red as the local blood flow increased, gastric juice was secreted, and gastric peristalsis was stimulated. If he made him angry or upset during this process, the gastric juice secretion and peristalsis markedly decreased and the stomach color grew paler.
Problems at the other end of the gut can also develop during stress. Some people develop diarrhea. Others become constipated. Often young children who are angry involuntarily refuse to move their bowels for one or two weeks or even longer. (The recorded record for an adult is a year and a day, and an operation was required, with the use of a hammer and chisel.)
One way to recognize the presence of IBS is to realize that disease is not cognizant of time, or the day of the week, or geography. So if you have GI problems during the week and not on weekends, maybe your job is stressing you out. If your stomach problems magically disappear when you are away on vacation, then maybe your daily responsibilities are causing a problem. Similarly, most people sleep very well on vacation, almost as if their insomnia decided to take a vacation along with their body. And of course if visiting someone or that someone visiting you distresses your gut, then that person is toxic for you for whatever reason. When your emotions are stressed your brain reacts by causing distress in your body, typically in your gut, and this is the brain's way of crying for help and relief.
And for the individual with functional bowel problems who says "I have nothing to feel stressed about", one can only hope that a kind and understanding family physician can help that person to understand the amazingly powerful mind-body connection.
We all have heard the expressions, and many of us have felt the sensation of "made me sick to my stomach", "made me throw up", "turned my stomach" "gave me agida or heartburn", "left a sour taste in my mouth", "my mouth turned dry", or "my mouth watered" , and thus are aware of the mind-body connection between our brain and our gut. The validity of these expressions was verified beginning in April, 1822. A French trapper, Alexis St. Martin, was accidentally shot in the stomach on Mackinac Island, Michigan, and healed by a Dr. William Beaumont. The healing left a hole directly into his stomach through the abdominal wall. Dr. Beaumont performed many experiments which he documented, including observing the color of the interior of the stomach wall, and the rate of digestion of a piece of meat dangled on a string into the stomach through the hole. He observed that when the patient got angry or upset, the stomach wall blanched indication a decreased blood supply, and the stomach muscles either stopped squeezing back and forth, or went into spasm. Under normal conditions, the stomach wall was pink. When he lowered a piece of meat into the stomach, the walls became red as the local blood flow increased, gastric juice was secreted, and gastric peristalsis was stimulated. If he made him angry or upset during this process, the gastric juice secretion and peristalsis markedly decreased and the stomach color grew paler.
Problems at the other end of the gut can also develop during stress. Some people develop diarrhea. Others become constipated. Often young children who are angry involuntarily refuse to move their bowels for one or two weeks or even longer. (The recorded record for an adult is a year and a day, and an operation was required, with the use of a hammer and chisel.)
One way to recognize the presence of IBS is to realize that disease is not cognizant of time, or the day of the week, or geography. So if you have GI problems during the week and not on weekends, maybe your job is stressing you out. If your stomach problems magically disappear when you are away on vacation, then maybe your daily responsibilities are causing a problem. Similarly, most people sleep very well on vacation, almost as if their insomnia decided to take a vacation along with their body. And of course if visiting someone or that someone visiting you distresses your gut, then that person is toxic for you for whatever reason. When your emotions are stressed your brain reacts by causing distress in your body, typically in your gut, and this is the brain's way of crying for help and relief.
And for the individual with functional bowel problems who says "I have nothing to feel stressed about", one can only hope that a kind and understanding family physician can help that person to understand the amazingly powerful mind-body connection.
Monday, April 30, 2012
Medical Statistics and Medical Errors, Part I
The field of medical statistics is poorly understood by many doctors and by most patients. An article in the New England Journal of Medicine that surveyed over 100 articles published in reputable medical journals stated that over 50% of them used medical statistics incorrectly, and furthermore stated that this misuse invalidated the clinical conclusions of many of these articles. In this blog I will not discuss esoterica such as when to use a two-tailed t-test rather than a one-tailed test, or the uses and misuses of the Cox regression analysis. Instead I will try to point out fallacies in reasoning and statistics that should cause you to doubt a result quoted in the journal or in the newspapers.
Let me begin by saying that except for out-and-out charlatans, no physician deliberately lies or misuses statistics in a paper. However, it is very easy to delude oneself when doing research. A classic example occurred to a physicist in France in the 1920's and 1930's who claimed to see special rays, called "N-rays" when a beam was passed through an aluminum prism. Only he was able to see these rays, which were subsequently proven to be nonexistent when an American physicist named Wood surreptitiously removed the prism and the rays were still seen by the French scientist. More recently, we can recall the Utah scientists who claimed to have produced "cold fusion" with a table-top experiment. In the distant past, I can refer you to the European horse, "Clever Hans", who was claimed by his owner to stamp his hoof four times when asked for the sum of two plus two, and was also observed to answer similar arithmetical questions. It was later shown that the horse was (subconsciously) interpreting minute muscular twitches of his master when the number of hoof stomps reached the desired answer.
Medical error can reach unimaginable heights. The Nobel Prize in Medicine was awarded to Dr. Egas Moniz in 1949 for work he did before WWII claiming to show that prefrontal lobotomies calmed and cured schizophrenic patients. There was no control group cited, and except for the surgery in "One Flew Over the Cuckoo's Nest" it is rarely if ever performed today. But schizophrenia was such a treatment-defying mental disease that the doctors became desperate to seize upon any procedure that seemed to promise a cure, including insulin-induced hypoglycemic shock. Again let me emphasize that the doctors believed that they were helping the patient, even though a true blinded clinical study had never been done.
I have already blogged twice about the statistical errors inherent in meta-analyses of clinical studies, and have published a critique of meta-analysis in the Volume 81 edition of "Chance", a statistical journal published by the mathematics department of Middlebury College, Vt. The point I want to make is that the proper use of meta-analyses is to suggest hypotheses which then should be tested in a proper double-blind clinical study. It is irrational and a violation of statistical theory to combine a number of non-significant clinical studies and thereby to claim a statistically significant clinical result. I can assure my readers that no such approach was ever taken to decide the speed of light or the mean distance of the earth from the sun.
I cannot emphasize enough the importance of paying attention only to articles and reports of clinical studies that are published in a refereed medical journal. The referee (and I have been both a referee and an associate editor for both physics and medical journals) wants to ensure that only statistically accurate clinical reports are published. This is a valuable filter because the referee has no axe to grind, and (should be) free from any bias. Thus the referee ensures that the article makes sense, is statistically and scientifically accurate, has enough patients in the study to make the result clinically important as well as statistically correct, and contains enough information that any other medical scientist could repeat the exact study.
Whenever you see a newspaper report about a medical study, you should try to at least get an abstract of the paper. The abstract is almost always available through PubMed.com, a library journal listing service managed by the National Institutes of Health. Many many times the newspaper, in an effort to simplify the scientific facts, misstates the results of the study. Needless to say, any TV interviews with a doctor should be taken with a large grain of salt, especially if he or she is publicizing a recently written book. Again, the gold standard is a refereed paper published in a reputable medical journal. And let us not forget how many times the clinical conclusions of a published article were refuted by the next clinical article that dealt with the same medical problem. That is why I always tell my patients to wait for and look for a second confirming article, and not to believe any medical "progress" that is written up in the National Enquirer.
As a final point, let me re-iterate the importance of differentiating between relative risk and absolute risk. The absolute risk is the benefit or risk you gain when compared with the total population of patients, while the relative risk compares you to other patients with your identical clinical problem(s). Anticoagulation can reduce the risk of a stroke in patients with atrial fibrillation. The absolute risk of stroke in patients without anti-coagulation may be 5% in two years, and the absolute risk of stroke for patients who are anti-coagulated may be 2.5% in two years. You can therefore claim, with equal validity, that anti-coagulation reduces the absolute risk by 2.5% in two years, or reduces the relative risk by 50% in two years and most newspaper results and PR results will quote the 50% relative risk reduction because it is a larger number and therefore sounds more significant to the uninitiated.
Let me close by citing verbs that should alert you to a non-scientific conclusion: if the results "suggest that", "can be interpreted as", "might mean that", "leads doctors to believe that", "indicates that", "can support no other conclusion", then run for the nearest exit, because such phrases never precede a statement in a physics journal about the measured half-life of the mu meson (2.2 microseconds at rest for those of you who are interested in the result).
Let me begin by saying that except for out-and-out charlatans, no physician deliberately lies or misuses statistics in a paper. However, it is very easy to delude oneself when doing research. A classic example occurred to a physicist in France in the 1920's and 1930's who claimed to see special rays, called "N-rays" when a beam was passed through an aluminum prism. Only he was able to see these rays, which were subsequently proven to be nonexistent when an American physicist named Wood surreptitiously removed the prism and the rays were still seen by the French scientist. More recently, we can recall the Utah scientists who claimed to have produced "cold fusion" with a table-top experiment. In the distant past, I can refer you to the European horse, "Clever Hans", who was claimed by his owner to stamp his hoof four times when asked for the sum of two plus two, and was also observed to answer similar arithmetical questions. It was later shown that the horse was (subconsciously) interpreting minute muscular twitches of his master when the number of hoof stomps reached the desired answer.
Medical error can reach unimaginable heights. The Nobel Prize in Medicine was awarded to Dr. Egas Moniz in 1949 for work he did before WWII claiming to show that prefrontal lobotomies calmed and cured schizophrenic patients. There was no control group cited, and except for the surgery in "One Flew Over the Cuckoo's Nest" it is rarely if ever performed today. But schizophrenia was such a treatment-defying mental disease that the doctors became desperate to seize upon any procedure that seemed to promise a cure, including insulin-induced hypoglycemic shock. Again let me emphasize that the doctors believed that they were helping the patient, even though a true blinded clinical study had never been done.
I have already blogged twice about the statistical errors inherent in meta-analyses of clinical studies, and have published a critique of meta-analysis in the Volume 81 edition of "Chance", a statistical journal published by the mathematics department of Middlebury College, Vt. The point I want to make is that the proper use of meta-analyses is to suggest hypotheses which then should be tested in a proper double-blind clinical study. It is irrational and a violation of statistical theory to combine a number of non-significant clinical studies and thereby to claim a statistically significant clinical result. I can assure my readers that no such approach was ever taken to decide the speed of light or the mean distance of the earth from the sun.
I cannot emphasize enough the importance of paying attention only to articles and reports of clinical studies that are published in a refereed medical journal. The referee (and I have been both a referee and an associate editor for both physics and medical journals) wants to ensure that only statistically accurate clinical reports are published. This is a valuable filter because the referee has no axe to grind, and (should be) free from any bias. Thus the referee ensures that the article makes sense, is statistically and scientifically accurate, has enough patients in the study to make the result clinically important as well as statistically correct, and contains enough information that any other medical scientist could repeat the exact study.
Whenever you see a newspaper report about a medical study, you should try to at least get an abstract of the paper. The abstract is almost always available through PubMed.com, a library journal listing service managed by the National Institutes of Health. Many many times the newspaper, in an effort to simplify the scientific facts, misstates the results of the study. Needless to say, any TV interviews with a doctor should be taken with a large grain of salt, especially if he or she is publicizing a recently written book. Again, the gold standard is a refereed paper published in a reputable medical journal. And let us not forget how many times the clinical conclusions of a published article were refuted by the next clinical article that dealt with the same medical problem. That is why I always tell my patients to wait for and look for a second confirming article, and not to believe any medical "progress" that is written up in the National Enquirer.
As a final point, let me re-iterate the importance of differentiating between relative risk and absolute risk. The absolute risk is the benefit or risk you gain when compared with the total population of patients, while the relative risk compares you to other patients with your identical clinical problem(s). Anticoagulation can reduce the risk of a stroke in patients with atrial fibrillation. The absolute risk of stroke in patients without anti-coagulation may be 5% in two years, and the absolute risk of stroke for patients who are anti-coagulated may be 2.5% in two years. You can therefore claim, with equal validity, that anti-coagulation reduces the absolute risk by 2.5% in two years, or reduces the relative risk by 50% in two years and most newspaper results and PR results will quote the 50% relative risk reduction because it is a larger number and therefore sounds more significant to the uninitiated.
Let me close by citing verbs that should alert you to a non-scientific conclusion: if the results "suggest that", "can be interpreted as", "might mean that", "leads doctors to believe that", "indicates that", "can support no other conclusion", then run for the nearest exit, because such phrases never precede a statement in a physics journal about the measured half-life of the mu meson (2.2 microseconds at rest for those of you who are interested in the result).
Tuesday, April 24, 2012
Some of my Thoughts
Below are some of my medical observations, some recalled facts from journal articles, and some of my thoughts and speculations. As do many other people, I tend to generalize, so if I write "men" or "women", please mentally substitute "the majority of", or "most". Some of these comments have appeared in earlier blogs.
1) It is not true that turning the thermostat up as high as it will go will heat your house faster.
2) Similarly, it is not true that if you are running low on gas you should drive faster to get to a gas station before your gas runs out.
3) When you are dating, you are on your best behavior. So if something about the other person bothers you, do not expect it to improve.
4) The Federal Highway Safety Board (see its Congressional testimony) knew from experiments with crash test dummies that airbags could be lethal or injurious to young children fastened in carseats in the front passenger seat, but they were so anxious to get the carseat law passed that they omitted this from their testimony.
5) In almost every state where mandatory seatbelt laws were passed, the death rate for pedestrians increased the first two years.
6) When I asked one of my children how getting a driver's license changed his life, he replied that he was now a much more careful pedestrian because he realized how difficult it was to see them.
7) There is a higher death rate for pedestrians who cross against the light in the middle of the block rather than at the corners, because drivers subconsciously look for pedestrians at the corners.
8) In an informal poll, over 90% of adults questioned who liked chocolate ice cream as a child could curl their tongues, and those who preferred vanilla could not. Why and how the motor XIIth cranial nerve is connected to the taste part of the VIIth (anterior tongue) and IXth (posterior tongue) cranial nerves is a mystery.
9) We don't know why some people sneeze violently as they leave a dark movie house during the day and emerge into bright sunlight.
10) Your fingernails and hair do NOT grow after your death: skin retraction secondary to dessication just makes it appear that way.
11) The majority of women who do the family wash throw out their husband's t-shirts if they have holes in them, and the husbands don't know why.
12) The women applauded and the men were shocked when Geena Davis threw the baseball game to her sister in "A League of Their Own". A male player would not even throw a professional game to his identical twin brother. And Early Wynn, a fastball pitcher for the Cleveland Indians who was known for his brushback and knockdown pitches was quoted as saying that he would even pitch his mother high and tight if she got a hit off him.
13) School rules are made by women for girls, and work rules are made by men for men and boys.
14) When a man tells another man or woman "I'll call you", it is generally understood by the other man but not by the woman that he means sometime between the present and his deathbed.
15) "Men are expected to be emotionally shallow"---Jerry Seinfeld.
16) In a study done at Cook County Hospital in Chicago, by looking only at blood types, it was found that in 10% of the live births it was medically impossible for the husband to be the father of his wife's child.
17) Why do schoolgirls usually have much neater handwriting than schoolboys? They both have equal manual dexterity.
18) Could Abraham Lincoln be elected president if he ran for that office today?
19) Pacific tuna is pink (as you see when you order sushi or sashemi tuna in a Japanese restaurant). Atlantic tuna, or albacore, has white flesh. Pink tuna was sold for years before white tuna came on the market, and people shied away from buying tuna with this new color. Then the white tuna sellers came up with a killer ad: "Our tuna is guaranteed not to turn pink in the can".
20) Brakes stop the tires, but the tires' friction with the pavement has to stop the car.
21) In my years in the Emergency Room of Columbia-Presbyterian I never saw a Cadillac driver with a fractured leg from an automobile accident, but I did see plenty of Volkswagen drivers. Moral: drive the biggest, heaviest car you can, such as an SUV. Probably half of your accidents are caused by the other driver, so you want him to bounce off you. In the same vein, I told all my children that I would never let them ride or own a motorcycle, and for the first six months after they got their driver's license I had them drive an old, heavy, Buick Estate station wagon.
22) No doctor ever got sued for doing an (unnecessary?) test, but many have been sued for not doing one.
23) Lawyers can charge for telephone advice. Doctors cannot, but they can be sued for giving bad advice over the phone. Some doctors refer all patients who call to the ER and/or tell them to come right away to their office for just this reason. In some states it is a violation of "sound medical practice" to give any medical advice if you have not seen the patient.
24) Why are seatbelts not mandatory in all schoolbuses in all states?
25) Did your money manager predict the 2008 bank crash? If not, why are you still allowing him/her to manage your money?
26) It is illegal to sell organs here, but not in India. Many patients with kidney failure both here and in England fly to India to buy a kidney and pay for the transplant.
27) On the island of Anguilla, there are five medical clinics: one family medical practice, one dental, and three plastic surgery.
28) New Jersey residents take their driving test in a parking lot. They do NOT take the test on a road with real traffic. To this day I have patients who will not drive on NJ highways because they never learned how to merge at high speed.
29) Why not mandate that the horn of any car in reverse sounds a beep-beep-beep as most trucks do?
30) All of us have emotional inertia, and hope/pray that the stresses of our job or our marriage will get better
without our doing anything about it.
1) It is not true that turning the thermostat up as high as it will go will heat your house faster.
2) Similarly, it is not true that if you are running low on gas you should drive faster to get to a gas station before your gas runs out.
3) When you are dating, you are on your best behavior. So if something about the other person bothers you, do not expect it to improve.
4) The Federal Highway Safety Board (see its Congressional testimony) knew from experiments with crash test dummies that airbags could be lethal or injurious to young children fastened in carseats in the front passenger seat, but they were so anxious to get the carseat law passed that they omitted this from their testimony.
5) In almost every state where mandatory seatbelt laws were passed, the death rate for pedestrians increased the first two years.
6) When I asked one of my children how getting a driver's license changed his life, he replied that he was now a much more careful pedestrian because he realized how difficult it was to see them.
7) There is a higher death rate for pedestrians who cross against the light in the middle of the block rather than at the corners, because drivers subconsciously look for pedestrians at the corners.
8) In an informal poll, over 90% of adults questioned who liked chocolate ice cream as a child could curl their tongues, and those who preferred vanilla could not. Why and how the motor XIIth cranial nerve is connected to the taste part of the VIIth (anterior tongue) and IXth (posterior tongue) cranial nerves is a mystery.
9) We don't know why some people sneeze violently as they leave a dark movie house during the day and emerge into bright sunlight.
10) Your fingernails and hair do NOT grow after your death: skin retraction secondary to dessication just makes it appear that way.
11) The majority of women who do the family wash throw out their husband's t-shirts if they have holes in them, and the husbands don't know why.
12) The women applauded and the men were shocked when Geena Davis threw the baseball game to her sister in "A League of Their Own". A male player would not even throw a professional game to his identical twin brother. And Early Wynn, a fastball pitcher for the Cleveland Indians who was known for his brushback and knockdown pitches was quoted as saying that he would even pitch his mother high and tight if she got a hit off him.
13) School rules are made by women for girls, and work rules are made by men for men and boys.
14) When a man tells another man or woman "I'll call you", it is generally understood by the other man but not by the woman that he means sometime between the present and his deathbed.
15) "Men are expected to be emotionally shallow"---Jerry Seinfeld.
16) In a study done at Cook County Hospital in Chicago, by looking only at blood types, it was found that in 10% of the live births it was medically impossible for the husband to be the father of his wife's child.
17) Why do schoolgirls usually have much neater handwriting than schoolboys? They both have equal manual dexterity.
18) Could Abraham Lincoln be elected president if he ran for that office today?
19) Pacific tuna is pink (as you see when you order sushi or sashemi tuna in a Japanese restaurant). Atlantic tuna, or albacore, has white flesh. Pink tuna was sold for years before white tuna came on the market, and people shied away from buying tuna with this new color. Then the white tuna sellers came up with a killer ad: "Our tuna is guaranteed not to turn pink in the can".
20) Brakes stop the tires, but the tires' friction with the pavement has to stop the car.
21) In my years in the Emergency Room of Columbia-Presbyterian I never saw a Cadillac driver with a fractured leg from an automobile accident, but I did see plenty of Volkswagen drivers. Moral: drive the biggest, heaviest car you can, such as an SUV. Probably half of your accidents are caused by the other driver, so you want him to bounce off you. In the same vein, I told all my children that I would never let them ride or own a motorcycle, and for the first six months after they got their driver's license I had them drive an old, heavy, Buick Estate station wagon.
22) No doctor ever got sued for doing an (unnecessary?) test, but many have been sued for not doing one.
23) Lawyers can charge for telephone advice. Doctors cannot, but they can be sued for giving bad advice over the phone. Some doctors refer all patients who call to the ER and/or tell them to come right away to their office for just this reason. In some states it is a violation of "sound medical practice" to give any medical advice if you have not seen the patient.
24) Why are seatbelts not mandatory in all schoolbuses in all states?
25) Did your money manager predict the 2008 bank crash? If not, why are you still allowing him/her to manage your money?
26) It is illegal to sell organs here, but not in India. Many patients with kidney failure both here and in England fly to India to buy a kidney and pay for the transplant.
27) On the island of Anguilla, there are five medical clinics: one family medical practice, one dental, and three plastic surgery.
28) New Jersey residents take their driving test in a parking lot. They do NOT take the test on a road with real traffic. To this day I have patients who will not drive on NJ highways because they never learned how to merge at high speed.
29) Why not mandate that the horn of any car in reverse sounds a beep-beep-beep as most trucks do?
30) All of us have emotional inertia, and hope/pray that the stresses of our job or our marriage will get better
without our doing anything about it.
Sunday, April 22, 2012
How to Interpret Medical News and Tests
There have always been and will always be news articles and TV news stories about the results of medical tests. Some of these articles will quote (usually incompletely and incorrectly) from a study published in a refereed journal, some will quote from a talk given at a medical conference, and some will be derived from an interview with a doctor whose research has come to their attention. One major problem, of course, is that the non-scientist has no way to judge the medical significance of such news reports, let alone whether or not the reported work fulfills certain basic requirements of scientific rigor. In this blog I will present some guidelines to help such readers and viewers evaluate the news report or interview.
Firstly, there are no real secrets in medical treatments. Everyone publishes their research, and, if it is significant, tries to get on Oprah's show. Failing that, the PR department of their hospital will issue news releases to local and national newspapers and magazines as well as to the TV media. All of us would like to become famous, respected by our peers, and rich, no matter what our field of endeavor, and keeping our successes secret is not the proper avenue to achieve this. For instance in the field of cancer, each hospital has its weekly tumor board meeting where interesting, challenging or puzzling cases and/or results are presented and discussed. Then in most large cities there is a monthly oncology get-together. There also are quarterly meetings around the country as well as an annual meeting, which meeting is always well-attended by the media.
Secondly, be careful about placing too much credence in any single report of a talk or paper delivered at a medical meeting. Such a report may or may not be clinically accurate, but until it is submitted for consideration to a refereed journal and is published, it is just one doctor's opinion. In my prior field of physics we recently had newspaper reports of an experiment which purported to show that neutrinos traveled faster than the speed of light, but a careful re-analysis of the data showed that they did not.
Third, it is essential to understand and appreciate the difference between relative risk and absolute risk. Absolute risk compares you to the entire world, e.g. you have a 10% chance of going bald if you are a man. Relative risk compares your subset to others in your group: if you are an American male, you have twice the chance of going bald than if you are Chinese. Researchers and reporters use relative risk to over-emphasize their results, and sometimes to stampede you into a certain behavior: the relative risk number is always larger than the absolute risk number because a subset (the denominator in risk calculations) is always a smaller number than the entire set of humans. If your chance of being hit by lightning is 1/2,000,000, or one in two million, and I can reduce your risk to 1/1,000,000, the absolute statement is that I reduced your absolute risk by 1/1,000,000 , or 0.0001%. OTOH I can say with equal validity, that I reduced your relative risk by one-half, or 50%. Always look to see the absolute number, because only that number has immediate relevance to your case.
Fourth, in connection with the degree of risk protection, we have the "number needed to treat", or NNT. That is, how many patients, based on the statistics of the study, would have to be treated by the drug or intervention in question in order to get one positive result (i.e. cure one patient, diagnose one disease, save one life, etc.). And note that they NEVER quote the NNS, or the number needed to treat to have one patient get a side effect, and usually the NNS is quite smaller than the NNT. Would you take a pill to prevent a heart attack if they had to treat 10 people to save one person from a heart attack? What about 100, or 1,000, or 10,000 or 100,000? And would you still agree to treatment if the NNS were 2, i.e. 50% of those taking the medicine or other treatment suffered a side effect?
Fifth, those patients who enrolled in a study group are probably not typical of the average patient, and the results quoted for them may not apply to you. The study group patients are highly motivated, have a strong interest in staying healthy, and are committed to seeing the doctor when scheduled. Also their reporting of side effects may not encompass all possible side effects if a question about the possible effect is not included on the questionnaire. A case in point is that a few men who took Viagra reported seeing a bluish tint to their field of view, a reaction that certainly was not looked for until it was first reported.
Then we have the case of honest error. Many clinical studies are not borne out when they are repeated by another researcher or research group. This is in part due to the fact that with commonly accepted statistical medical analysis there is at least a 5% chance that the beneficial conclusion was reached by error.
Or it may be simply that the second study group differed in some important way from the first. There are many, many cases of the New England Journal of Medicine, or Lancet publishing back-to-back articles which come to opposite conclusions about a seemingly identical clinical treatment of the same medical problem.
You should also be aware of the placebo effect. Many studies have demonstrated a placebo effect of 30% across the board. In other words, taking a sugar pill or an injection of normal saline can produce a beneficial effect.
This may be related to the fact that almost all patients feel instantly better as soon as the doctor walks into the examination room wearing a white coat. The human brain is a marvelous organ, and the mind-body interaction is always occurring, either on an unconscious or subconscious level. Believing can sometimes make it so, but we don't know how to engender that believing on a consistent basis.
Finally, distrust all medical advertisements about the wonderfulness of the doctor or clinic or hospital doing the advertising. If they were that wonderful, they would not need to advertise. I especially dislike the ad (hospital name deliberately omitted) "Cancer. Where you're treated first can make all the difference." The insidious suggestion is that if you do not go to them for treatment and your cancer spreads you only have yourself to blame!!!
Firstly, there are no real secrets in medical treatments. Everyone publishes their research, and, if it is significant, tries to get on Oprah's show. Failing that, the PR department of their hospital will issue news releases to local and national newspapers and magazines as well as to the TV media. All of us would like to become famous, respected by our peers, and rich, no matter what our field of endeavor, and keeping our successes secret is not the proper avenue to achieve this. For instance in the field of cancer, each hospital has its weekly tumor board meeting where interesting, challenging or puzzling cases and/or results are presented and discussed. Then in most large cities there is a monthly oncology get-together. There also are quarterly meetings around the country as well as an annual meeting, which meeting is always well-attended by the media.
Secondly, be careful about placing too much credence in any single report of a talk or paper delivered at a medical meeting. Such a report may or may not be clinically accurate, but until it is submitted for consideration to a refereed journal and is published, it is just one doctor's opinion. In my prior field of physics we recently had newspaper reports of an experiment which purported to show that neutrinos traveled faster than the speed of light, but a careful re-analysis of the data showed that they did not.
Third, it is essential to understand and appreciate the difference between relative risk and absolute risk. Absolute risk compares you to the entire world, e.g. you have a 10% chance of going bald if you are a man. Relative risk compares your subset to others in your group: if you are an American male, you have twice the chance of going bald than if you are Chinese. Researchers and reporters use relative risk to over-emphasize their results, and sometimes to stampede you into a certain behavior: the relative risk number is always larger than the absolute risk number because a subset (the denominator in risk calculations) is always a smaller number than the entire set of humans. If your chance of being hit by lightning is 1/2,000,000, or one in two million, and I can reduce your risk to 1/1,000,000, the absolute statement is that I reduced your absolute risk by 1/1,000,000 , or 0.0001%. OTOH I can say with equal validity, that I reduced your relative risk by one-half, or 50%. Always look to see the absolute number, because only that number has immediate relevance to your case.
Fourth, in connection with the degree of risk protection, we have the "number needed to treat", or NNT. That is, how many patients, based on the statistics of the study, would have to be treated by the drug or intervention in question in order to get one positive result (i.e. cure one patient, diagnose one disease, save one life, etc.). And note that they NEVER quote the NNS, or the number needed to treat to have one patient get a side effect, and usually the NNS is quite smaller than the NNT. Would you take a pill to prevent a heart attack if they had to treat 10 people to save one person from a heart attack? What about 100, or 1,000, or 10,000 or 100,000? And would you still agree to treatment if the NNS were 2, i.e. 50% of those taking the medicine or other treatment suffered a side effect?
Fifth, those patients who enrolled in a study group are probably not typical of the average patient, and the results quoted for them may not apply to you. The study group patients are highly motivated, have a strong interest in staying healthy, and are committed to seeing the doctor when scheduled. Also their reporting of side effects may not encompass all possible side effects if a question about the possible effect is not included on the questionnaire. A case in point is that a few men who took Viagra reported seeing a bluish tint to their field of view, a reaction that certainly was not looked for until it was first reported.
Then we have the case of honest error. Many clinical studies are not borne out when they are repeated by another researcher or research group. This is in part due to the fact that with commonly accepted statistical medical analysis there is at least a 5% chance that the beneficial conclusion was reached by error.
Or it may be simply that the second study group differed in some important way from the first. There are many, many cases of the New England Journal of Medicine, or Lancet publishing back-to-back articles which come to opposite conclusions about a seemingly identical clinical treatment of the same medical problem.
You should also be aware of the placebo effect. Many studies have demonstrated a placebo effect of 30% across the board. In other words, taking a sugar pill or an injection of normal saline can produce a beneficial effect.
This may be related to the fact that almost all patients feel instantly better as soon as the doctor walks into the examination room wearing a white coat. The human brain is a marvelous organ, and the mind-body interaction is always occurring, either on an unconscious or subconscious level. Believing can sometimes make it so, but we don't know how to engender that believing on a consistent basis.
Finally, distrust all medical advertisements about the wonderfulness of the doctor or clinic or hospital doing the advertising. If they were that wonderful, they would not need to advertise. I especially dislike the ad (hospital name deliberately omitted) "Cancer. Where you're treated first can make all the difference." The insidious suggestion is that if you do not go to them for treatment and your cancer spreads you only have yourself to blame!!!
Subscribe to:
Posts (Atom)