Let Them Eat Cake

Should I Give My Kid The Swine Flu Vaccine?

Rob Siegel, M.D. — Sat, 24 Oct 2009 00:21:24 +0000

Mother:

I am debating whether Caitlin should get the H1N1 shot tomorrow. I am not inclined to give her the normal flu shot, mostly because I prioritize vaccines for measles and other things that seem more life-threatening, but H1N1 is scarier. She's 17 months old. What do you think? (names changed)

Rob:

This vaccine, like nearly every effective treatment ever made, has dangers. The relevant question is not whether danger exists, but whether likely benefits outweigh likely harms.

In prior years the flu vaccine's ability to reduce death was much greater than its likelihood of causing any side effect more serious than a sore arm.

In otherwise healthy kids Caitlin's age who got flu last spring, the probabilty of death from H1N1 "swine" flu was between .001 and .0001; the probability of serious side effects in flu vaccines historically ranges around .00001-.000001. The incidence of H1N1 flu this upcoming fall is unknown, and is important in this analysis.

Studies on the new vaccine could not determine the risk of serious side effects because no serious side effects were reported so far in over 39,000 people who have received it. These studies found that the vaccine is good at preventing swine flu.

Between now and when you'll have to decide what to do for Caitlin, it's unlikely that we will obtain new, useful information to help guide this decision.

Will this vaccine be different from prior flu vaccines?

It's probably just like every other flu shot. It was made using the same process to make the standard seasonal flu vaccine.

There could always be a new, common, and devastating side effect with this vaccine--just because something has never happened before doesn't make it impossible (e.g. Popper's black swan, also the 2008 housing crisis).

You said the process for making H1N1 vaccine was the same as for prior flu vaccines. Why then are there all these worries about the safety of it?

If there is any scientific basis for the worry, I am not aware of it. Popular culture concerns over health issues follow a rhythm and a logic that I do not understand. Did you read the New Yorker article about the 1920's Parrot Fever Panic that spread in the US? It probably addresses your question better than I can.

Why didn't they just include H1N1 as one of the flu strains in the seasonal flu vaccine?

Timing. It takes a while between when we identify a pathogenic flu strain and when we can create a vaccine, establish saftey/efficacy, and produce hundreds of millions of doses. If the swine flu outbreak last winter had begun a few months sooner, then there would have been enough time to incorporate the swine flu vaccine into the seasonal vaccine this year.

For other flu shots, last year's seasonal flu shot for example, do they test the safety of that specific flu shot before distributing it for widespread public use?

Yes. Same process.

Do you think that if we waited another month we'd have any more info - if the 39,000 people were to become 100,000, for example, as a result of widescale vaccination campaigns?

Sure, but this also increases Caitlin's risk of catching swine flu during the wait.

One more - what is the likelihood of side effects occurring a while after the vaccine - i.e. for the 39,000 people to be fine now but develop a problem sometime in the near future? How long does Guillain-Barre take to manifest?

Another good question.

And a tricky one. Some scientists argue that the flu vaccine does not cause Guillain-Barre syndrome (GBS), and that the extra GBS cases we saw during the 1976 round of flu vaccination were coincidental. It's usually challenging to establish causality in anything that's occurring in 1 in 100,000 people. I don't have an opinion here.

How much time passes between vaccine administration and GBS? I don't know the answer. I suspect the data set we have on this is so tiny that you can't figure it out--which is to say, I'm guessing that it is not knowable. For what it's worth, I've never seen a case of GBS in my 10 years of doing medicine. Here's more info on the history of GBS and the flu vaccine:

http://www.nytimes.com/2009/05/09/health/09vaccine.html

What's your personal opinion?

I'm getting my H1N1 shot in the next few weeks; got the seasonal shot 3 weeks ago. "Doctors aim to prevent death. The long-term death rate is 100%. Therefore, all doctors are failures."

Let Them Eat Cake

Rob Siegel, M.D. — Mon, 11 May 2009 15:14:30 +0000

What unpleasant things do you do for the sake of your health? Doing these things takes some pleasure out of life, so it seems worthwhile to ask how much healthier you become.

Two Heart Attacks, Two of Life's Pleasures Lost

Mr. B., previously a lifelong smoker, had a heart attack shortly after turning fifty. At his wife's insistence he has quit smoking. He reports that he constantly craves cigarettes, dreaming of smoking almost every night.

Mr. G., a former colleague's father, was a coffee lover. He had a heart attack in his seventies. He read a pamphlet saying that you should avoid caffeine after a heart attack, and never drank coffee again. Instead he started drinking Postum, a coffee substitute.

At first glance these stories seem similar, stories of people making a sacrifice for the sake of better health.

Prolonging Life or Suffering Pointlessly?

Quitting smoking prolongs life in nearly everyone. It reduces your risk of having a heart attack; in people who have already had a heart attack, it reduces your risk of having another one. This effect is large, easily measurable, and repeatedly demonstrated. You could argue that it is the most thoroughly proven public health recommendation ever made; if not, it's close.

On the other hand, there is essentially no evidence to show that avoiding caffeine improves health after a heart attack. In the past some people suggested that drinking caffeine might cause a heart rhythm abnormality called ventricular ectopy (VE), which is associated with bad outcomes after heart attack. Eventually someone got around to doing a study to see if this was true, and it failed to find any effect of caffeine on VE in people who had heart attacks. The American College of Cardiology (ACC) last weighed in on this question in 1996, stating that it was safe to drink several cups of coffee a day even immediately after a heart attack.

However, before this study was done, some sources recommended avoiding caffeine after heart attacks, a recommendation that found its way to Mr. G.

"Better safe than sorry" v. "Postum Tastes Gross"

There is some merit to making health recommendations as soon as there's any concern for possible danger. Once we have some suspicion that something (e.g. coffee or cigarettes) might cause harm, perhaps you should avoid it until clinical trial data becomes available. It's sad that Mr. G. gave up coffee, but what about the people who heeded early warnings about cigarettes? Probably thousands of people avoided premature death from quitting smoking before the benefits of quitting became clear. In comparison, Mr. G.'s suffering seems trivial.

Except for one detail: By the time Mr. G. had his heart attack, the pamphlet was obsolete. The study showing that caffeine did not increase VE had already been published; the ACC had already declared coffee to be safe for him. He gave up coffee not out of caution, but because his news was old.

Thesis Statement for This Blog

This blog is dedicated to Mr. G., and to everyone else who is doing something that they don't enjoy for the sake of their health. We will look at things we do that:

1) Make life less enjoyable, yet
2) Have only minimal evidence of health benefit

This blog will revisit old warnings and examine new ones. It will investigate how health recommendations are made, and what they mean. We will meet the recommenders. We will ask these people uncomfortable questions to see if it might make you more comfortable.

This blog will not warn you of possible new health threats. Plenty of sources will take care of this for us--those people can tell you when avoid life's pleasures. Here you can learn about when it's safe to go back to enjoying life.

What's up with "Colon Cleansing?"

Rob Siegel, M.D. — Thu, 16 Apr 2009 01:14:03 +0000

Pooping is free! Why do people pay for it?

Drove past a van on my way home today; the van advertised "Cleanse Your Colon," with a phone number under the ad. What can this tell us about our modern age?

1) Creepy people love vans.
Everyone knows that a windowless van is a crucial tool for anyone with a creepy agenda. We learned this from The Silence of the Lambs.

2) Some Americans have wacky health beliefs.
This website showed us this. All you have to do is mention one of the least controversial statements in the history of scientific research: "fluoride administration reduces cavities," and these wing nuts appear on your blog's comments page.

3) Many people enjoy telling others what to do.
These people often find themselves in careers in health. The power in these jobs comes with a noble justification, a veneer or selflessness: Do what I say because it's good for you. You will feel better if you follow my expert advice-Ignore me at your own peril!

Back when this relationship started, the advice was terrible. People donned costumes, stoked their reputations as experts, then told people what to do. Many patients embraced this system, eager to have experts tell them what to do. Mostly they did things with dramatic although probably mostly harmful effects, such as applying leeches to skin or administering mercury in high enough doses to cause mercury poisoning. All you needed was a theory and some gravitas.

4) Some people will pay you to give them diarrhea.
Okay, I admit: The people who do colon cleansing know more about this than I do. I don't know the risks and benefits of taking mega-doses of laxatives, or about getting enemas. Help me learn! Hey, colon cleansing practitioners out there, a favor: When you comment, could you please let me know how you address the following questions:

How do you know that it provides benefit?
How do you know that it's safe?

These questions: They are among the most important topics in health care. Rephrased: Which treatments are likely to help, and which are not?

I feel sad when people with unsophisticated answers to these questions make health recommendations. Not that I should care. I can whine all day about how I spent years learning sophisticated methods of evaluating the responses to the questions above. Some of my colleagues have gone to extravagant lengths to design clinical trials designed to give the best possible information that can help people know which treatments are likely to help.

Other people seem to take a different approach, advertising van-side: "I know what's good for you! Ignore all those doctors with their fancy science and their fetish for evidence. Instead, give me cash and I'll give you diarrhea!"

This is not to say that all doctors give sound, evidence-based advice all the time. Some people who have earned medical degrees also practice without much regard for clinical evidence. Others spew misleading corporate propaganda for profit. Well-meaning, honest doctors sometimes don't know evidence that's relevant to their patients, and sometimes fail to provide optimal therapy because of this. (It's impossible to know everything, but many of us try our best.) Available evidence has flaws, too, but it has transformed hundreds of previously lethal or permanently disabling diseases into oddities; factoids that only rarely affect us. (People used to die of Lockjaw!) The majority of us, though, are trying our best to give sophisticated, evidence-based therapy, and are doing a reasonably good job most of the time.

In fact, I'm trying so hard to learn about clinical evidence that I have a favor to ask any colon-cleansing practitioners reading this: Please educate me. Show me why I'm wrong when I search the literature and conclude that you don't really know if colon cleansing treatment is better for you than avoiding colon treatments. Tell me what you know. The link to the comments section is below.

Doctor’s Diary: Drug Companies Buy My Booze

Rob Siegel, M.D. — Thu, 01 Jan 2009 20:51:16 +0000

Starting today the pharmaceutical industry has agreed to stop handing out the prescription-drug-branded trinkets you see in doctor's offices. No more flimsy Lipitor pens, no more Zithromax children's games, no more Viagra soap dispensers. However, drug companies will not change their policies concerning taking doctors out for "educational" dinners that turn into lavish events.

As drug companies have lose other avenues for advertising to doctors, these lush evenings will become one of the few ways the companies will still be able to try to manipulate doctors into prescribing their products.

The marketing people at Novartis bought me dinner recently. For those of you who can't enter this by-invitation-only world, here's your chance to learn what happens at these events.

(Ordinarily I avoid drug dinners. Receiving free stuff from drug companies feels like graft to me. Due to social entanglements, I felt obliged to attend this particular dinner. Call me a modern-day George Washington Plunkitt, but I value loyalty toward my friends over most principles, and this loyalty pushed me to attend.)

Three drug company representatives set up some tables in a back room in the chic sushi restaurant Bond Street. Two were attractive, blond, twentysomething women whose main job appeared to involve setting up a gizmo that would project a PowerPoint presentation onto a screen. The third was a friendly woman who frequently comes around my department in the hospital. Seeing how frequently she appears in my life, I suppose that she's in charge of getting me to prescribe Novartis drugs more often.

The wait staff came by to offer us free drinks, and I promptly downed two.

NYU hypertension specialist Howard Weintraub gave a presentation about the drug, a blood pressure medication called Tekturna. He filled his talk with "doctor jokes," quips that require extensive background in medical knowledge and patient treatment before you can "get" them.

There is no evidence that this drug makes people live longer or feel better. Sure, there's evidence that it lowers blood pressure. However, lots of treatments lower blood pressure while worsening health. He went over the useless evidence on its effect of blood pressure, peppering his talk with these doctor jokes. Many of these jokes expressed sympathy with his co-physicians for the forces that make our lives difficult; most had some element that flattered the intelligence of the audience. His speaking style fell somewhere between Rodney Dangerfield and stereotypical-car-salesman.

I tried to pay attention to evidence he could provide that this drug makes people live longer or feel better. Paying attention was difficult: My spot at the table kept me angled away from the screen that displayed his presentation. The booze did not help: Before he started speaking I had already become tipsy.

(Thank you, Novartis! Thank you, patients who pay out-of-pocket for Novartis drugs! Thank you, taxpayers and insurance buyers who put money into a health care system that spends money on Novartis products. Cheers! Who cares if we don't get any more crap-tastic pens if we keep getting this?)

Hey, cute blondes, come talk to me! Another time when I ended up at one of these events, a medical device company's beautiful young representative kept asking me questions and pretending to be interested in me and my life for about an hour. With the benefit of hindsight and sobriety I feel sorry for her-how dull!-and ashamed of myself. It feels pathetic to spend much time with people who are paid to act friendly with you. I wonder how my colleagues feel when the drug cuties feign interest in them. This night's blondes never approached me, and, with me wedged into the corner and blotto, going to them seemed insurmountably difficult.

At one point the speaker admitted that nobody knows whether the drug extends life, but that they were doing a study to investigate this. The world already has several blood pressure medications that do make people live longer. Several of these drugs have a long safety record and a low price. Does Novartis think that I'll start prescribing their new, expensive, possibly useless drug instead?

Maybe.

Coming eventually: A blog entry on My Colleagues Who Prescribe Expensive Untested Drugs When Inexpensive and Effective Alternatives Exist. Later, you might also get an entry on the hypocrisy of accepting a meal from a drug company, then writing a snarky blog entry about the ethics of the whole practice.

Cholesterol, Kids, and Screaming "Shamefully!"

Rob Siegel, M.D. — Fri, 11 Jul 2008 20:39:08 +0000

Outraged about giving cholesterol medicine to kids?

This week the American Academy of Pediatrics (AAP) issued a policy statement recommending that kids receive blood tests to check their cholesterol levels, and to start cholesterol medication in some who have high cholesterol.

Pandemonium ensued! Comments on a New York Times site on this subject showed people seething with anger. Here's an example:

"Wow, this is just so wrong in so many ways. Shamefully!
"Why isn't the American Academy of Pediatrics instead saying, no, URGING people to stop eating chain restaurant food, fake food, etc.? Isn't it better, smarter, and wiser for them to strongly encourage people to stop eating at McDonalds, drinking Coca-Cola and other processed stupid food and beverages?"

That post came from somebody with the handle "Jack." If you're out there, Jack, I'd like to invite you to come to work with me to meet a patient who we will call "Susan." We talked about your post yesterday, and she would like to meet you.

She is a 39-year-old woman who had a heart attack on the same day that the AAP issued these controversial guidelines. This caused so much damage to her heart that her body is connected to a device called an intraaortic balloon pump that helps her heart deliver blood to her body. Without this device, blood flow to her brain would drop so drastically that she would die. Eventually she will require some sort of surgery--perhaps bypass surgery or implantation of a permanent heart-assist pump--in order to leave the hospital. For now she's unable to get out of bed.

Susan obviously wishes that she never had this heart attack, and feels puzzled about Jack's comment. She understands that she did not lead a perfect lifestyle, but she did not lead a particularly bad one, either. Mostly she wishes that she did not suffer from such a bad case of her underlying disease--coronary atherosclerosis--and wishes that it had not become so severe that it caused a heart attack. She agrees that we should do things that are likely to protect protect the hearts of today's kids, including (but certainly not limited to):

1) Healthier lifestyle, including exercising more and eating healthier foods, and
2) Cholesterol medication to try to prevent coronary atherosclerosis, possibly starting at the young age when atherosclerotic plaque begins to form

Jack, I agree with you about the importance of a healthy lifestyle. However, I'm not sure why you oppose number two. If Susan had started taking cholesterol medications when she was 8 years old, and if that had prevented her heart attack, would you change your mind? Would you insist that she suffer the heart attack that's making her lie in bed with this pump in her chest? After all, the problem is atherosclerosis, which has many causes, including, but not limited to, an unhealthy lifestyle.

I imagine that Jack might respond, "a better lifestyle alone might have been adequate to save her." True--sometimes this strategy will succeed. But sometimes it will fail. Avid runner Jim Fixx demonstrated this--despite leading an extraordinarily healthy lifestyle, he died of a heart attack at age 52. Would he still be alive if he had received cholesterol drugs as a kid?

It's not certain that cholesterol medicines would have saved Fixx, or Susan, or any other individual. However, we have lots of evidence about what happens when carefully selected people at high risk for heart attack take cholesterol medication: On average, they live longer, healthier lives. Some people have side effects, but repeated studies have demonstrated that the benefits outweigh the risks in the right population.

Some experts agree with Jack's statement. Dr. David Ludwig, director of the childhood obesity program at Children's Hospital in Boston, commented on the AAP recommendation:

"My concern is what this is saying about society when we are so quick to prescribe drugs for these conditions before having systematically attacked the problem from the public health perspective."

Dr. Ludwig, what it's saying is that our society cares so much about people like Susan that we're willing to take an aggressive approach to prevent heart attacks. When will you declare that society has "systematically attacked the problem from a public health perspective?" Until that time, should we refuse to offer new preventive treatments to people at high risk of a heart attack? How many people should suffer preventable heart attacks while you work through your concern about what kind of society you want to live in?

To those who work at the AAP: We don't know how many people will have to take cholesterol medication in this new strategy in order to save one life. I disagree with your recommendations on the technical grounds, summarized in this thoughtful critique. However, Susan and I hope that you will ignore the insults coming your way. You're trying to save lives, and, even though I disagree with you on the details, I applaud your efforts.

Is Sunlight Good or Bad for You? (The Real Answer Is Here!)

Rob Siegel, M.D. — Mon, 31 Mar 2008 01:25:19 +0000

Sunlight causes cancer (bad)! It also helps us make vitamin D (good). Should we avoid it? On Wednesday the Indoor Tanning Association ran a full-page ad in the New York Times with their opinion (pdf). Are they correct?

Patients complain to me that medical research seems flawed because health recommendations seem to change; news reports suggest that doctors flip-flop with our opinions. However, we doctors are able to make sense out of all this, and you can, too. To understand the controversy surrounding sunlight and many other medical issues, the most important thing to know is:

Understand the strength of the evidence behind a health claim. For example, we are essentially certain about these statements:

-Fluoride reduces risk of cavities
-Cigarette smoking increases risk of premature death

On the other hand, we are uncertain about these:

-Avoiding sunlight reduces risk of skin cancer
-Obtaining vitamin D from sunlight improves health

The cases of fluoride and cigarettes help explain today's sunlight controversy.

We became certain about the effects of fluoride and cigarettes for several reasons. It is easier to detect something that has a powerful effect on health than to detect something with a subtle effect. Fluoride is especially good at preventing tooth decay, and cigarettes are particularly effective at killing people. Because these effects are so powerful, it's hard for scientists to fail to notice them.

Additionally, fluoride and cigarettes received unusually thorough attention because nonscientists generated controversy about them. Young readers may not know about the success of the tobacco lobby in creating confusion about whether or not cigarettes are bad for you. Also, some people used to argue that fluoride was a communist plot designed to poison American children in order to help Soviets conquer the world. These agendas seem ridiculous today, but they seemed somewhat reasonable thirty years ago. Social controversy pushed scientists to continue studying these claims even after they had become reasonably certain, making them among the most thoroughly proven claims in all of medicine.

Sunbathing also generates controversy among nonscientists, but scientists have not provided much useful information on this topic. There are problems with the few studies that have found harm from sunlight. (Here is a summary of the currently available evidence concerning sunbathing.) Why is the evidence so weak? We don't even know the answer to that yet. So long as scientists don't have good answers, the suntan lotion industry and the indoor tanning industry will continue to finance publicity endeavors such as SunLightScam.com, the site listed on the Times advertisement.

That site prominently declares that vitamin D from sunlight provides health benefits, but what's their evidence? They do not cite any studies. The only reference they provide is a link to a Newsweek health blog. And you, dear reader, understand that information in national magazine health blogs can be unreliable.

The bottom line: Sunbathing may be good for you, or it may be bad for you. We just don't know. The strength of the evidence is too weak to make decent conclusions at this time. Former Defense Secretary Donald Rumsfeld, while talking about something else, summarized the epistemology of health recommendations:

As we know,  
There are known knowns.  
There are things
we know we know.  
We also know  
There are known unknowns.  
That is to say  
We know there are some things  
We do not know.  
But there are also unknown unknowns,  
The ones we don't know  
We don't know.

-Feb. 12, 2002, Department of Defense news briefing

This blog is not intended to diagnose, treat, cure or prevent any condition or disease. Please consult with your own physician or health care specialist regarding the suggestions and recommendations made within.

The Claim: Caffeine Causes Birth Defects

Rob Siegel, M.D. — Fri, 21 Mar 2008 15:24:27 +0000

My pregnant friend has studiously avoided cats (toxoplasmosis), alcohol (fetal alcohol syndrome), tuna (mercury), soft cheese (listeriosis), and sushi (oy gevalt). Recently she sent me this, wondering if she should also give up her daily macchiato habit:

“Too much caffeine during pregnancy may increase the risk of miscarriage, a new study says.”
New York Times, January 21, 2008, “Pregnancy Problems Tied to Caffeine”

This finding is surprising because no serious clinician has any idea how this could possibly work. Most miscarriages are caused by chromosomal abnormalities. Caffeine does many things, but nobody has ever shown that it harms chromosomes. It’s difficult to imagine how caffeine could possibly cause miscarriage. Is this harm real?

Anytime the press reports a possible peril to a developing fetus, it’s easy for the report to add an item to the list of pleasures that are prohibited during pregnancy. Here’s how:

Pretend that we’re concerned that watching television might harm a fetus. (It sounds plausible, right? As a society we believe that some things are likely to cause harm that we do not yet know, and these things include caffeine and television.) Let’s do a thought experiment that could make a medical researcher famous.

1) Give questionnaires to some women. Ask how much TV they watched during pregnancy.
2) Ask about lots of bad things that could possibly happen to a developing child: Obesity, prematurity, attention-deficit-hyperactivity disorder, and more.
3) Send the questionnaires to statisticians; instruct them to analyze the results in hundreds of ways.

If you analyze imperfect data in enough ways, you can always find some meaningless, coincidental correlation. Biostatisticians call this practice “data dredging.” This technique frequently yields misleading results, but some researchers do it anyway. This is how the caffeine/pregnancy study was done. Our health journalists could have ignored this exercise in data dredging, but, instead, they broadcasted it on TV.

Back to the thought experiment. Imagine that the statisticians dredge up a correlation between watching television in pregnancy and having a child with Down syndrome.

4) Publish the result.

Down syndrome, just like miscarriage, is caused by a chromosomal problem. It’s completely unknown how television—or caffeine—could possibly harm chromosomes. However, now the American Pregnancy Association states that women should minimize caffeine intake, even though they acknowledge that studies on this topic have been “inconclusive.” How do they explain their recommendation? “It is still better to play it safe when it comes to inconclusive studies.”

Our television study was also inconclusive. I suppose it’s always better to “play it safe,” after every study result, no matter how flimsy. No more coffee (miscarriage) or TV (Down syndrome) for pregnant mothers!

Yes, this thought experiment is inane. However, it’s difficult to show how it is different from the caffeine study. There are other, worse flaws with the methods of the caffeine study, making it difficult to conclude anything from it. Good science may someday show that tiny amounts of caffeine in pregnancy cause harm. However, seeing how little we know, it may turn out that caffeine is actually beneficial in pregnancy. We just don’t know. This study didn’t tell us any more about caffeine than our thought experiment told us about television.

This is not trivial. Thousands of women will suffer headaches from caffeine withdrawal as a result of this study. In exchange for their headaches, these women receive protection from a condition that caffeine probably cannot cause.

Let them drink coffee.

*The proper study design to answer this question is a randomized, placebo-controlled, double blind clinical trial. This sort of data dredging study—the one reported in the Times—is, as described above, largely useless for answering a clinical question.

This blog is not intended to diagnose, treat, cure or prevent any condition or disease. Please consult with your own physician or health care specialist regarding the suggestions and recommendations made within.