Monthly Archives: January 2011

Any “news” about breast cancer generates press coverage, and it is especially fun for the reporters if they can blame the victims’ own unsavory behavior, like smoking.  The latest such story (e.g., here) has so many interesting aspects that it is difficult to cover all of them.

First, why?  The study reported a slightly elevated risk of breast cancer for some smokers.  I can understand why a student might want to crunch the numbers on this as a project, but why is it news?  We already know that smoking is bad for you, and even if the press release about this were accurate, it would not change that much.  Who, exactly, is on the fence about smoking, thinking “if it were a bit less healthy I would quit, but I am fine with it now.”  Moreover, such a discovery would not really tell us it is a bit less healthy than we thought:  We already know the overall longevity and health outcomes for smokers vs. nonsmokers, so all this would do is explain some of the total impact.

On the same note, this result should not be touted as news because overall the studies of smoking and breast cancer have found no measurable effect.  Smoking is such an intense and complicated exposure that there are few health outcomes that it does not effect (most of the effects are bad, a few are good), so it seems reasonable to think that breast cancer is affected to some extent.  But we have a lot of evidence that the effect is small and not really worth mentioning compared to the other risks from smoking and other causes of breast cancer.  As with any well-studied small effect, there are some studies that show a positive association like this one (that is, it looks like the exposure causes the disease) and some that show a negative association (that is, it looks like the exposure might protect against the disease).

Second, this study, in itself, fits that description.  That is, it finds that smoking is sometimes associated with breast cancer, but sometimes protective against it.  Did you miss that bit in news stories?  Unless you live in Los Angeles, where the paper sort of pointed that out, that is not too surprising.  It turns out that the study estimated a positive association with smoking in one’s youth, but a protective association with smoking post-menopause.  The two estimated associations are about the same size, and they come from the same study, so if you are going to believe one, you are obliged to believe the other.  That is, if you are going to say, “here is a good reason for young women to not smoke,” you need to also say, “here is a reason post-menopausal women might want to start smoking” (or, perhaps more realistically, “if you are still smoking at menopause, here is a reason to not quit”).  It is difficult to imagine a more patent form of intellectual dishonesty than picking only the result that supports your political views and ignoring a comparable point from the same source just because you do not like it. 

Of course, it would be better to say “this does not imply it is good to smoke post-menopause because the other risks outweigh any benefit this result implies”, but that would require admitting, “this really does not change the arguments against smoking either, since any effect is quite small compared to the known risks.”  The accurate interpretation is that both estimated effects are small, and are really just curiosities.  Moreover, in the greater context of what is known about smoking and breast cancer, this one study should change our beliefs very little anyway.  The study should have been treated like a new study in astrophysics –  something for technical experts to use, and perhaps to be published in the  news for people who like to read science news for amusement, but not run as a headline as if we should really care about it.

Third, learned readers should notice that this result came from the Nurse’s Health Study.  That does not make it wrong, but it should make you suspicious.  That long-running cohort study is largely responsible for the opinion that many experts in epidemiology have, as I noted earlier, that nutritional epidemiology is mostly junk science.  That study collects zillions of variables about its participants every year, so it is possible to study countless topics – or dredge for associations among the data and publish whatever randomly appears.  A few researchers who have violated the code of omerta that surrounds the study have told me how the researchers who control it assign junior researchers particular topics and forbid publication of results that contradict claims made by previous researchers in the group.  These factors, plus the fact that the data is a closely guarded secret, make this study the epitome of how epidemiology often violates the fundamental norms of proper science.

Just to mention a second story which is not actually about breast cancer, though you would probably not know that from the headlines, it was discovered that breast implants apparently increase the risk of a rare cancer.  This was only discovered because the cancer is so extremely rare that just a few cases of it – there are about 60 cases reported among the perhaps 10 million women who have had implants – is enough of an increase to be noticeable.  It turns out that this is not even breast cancer, but a lymphoma (a cancer of the immune system) that occurs in the scar tissue that is created.

To their credit, neither the U.S. FDA who reported this, nor any other reputable actor, is suggesting that this ought to affect anyone’s decision.  This cancer is easy to treat, and the risk from the anesthesia for the surgery completely swamps it.  Indeed, it is down in the range of the risk from the car trips required to arrange and get the surgery. 

The major thing that these stories do have in common is that they are hyped beyond the minor technical curiosities that they are, and that neither one represents a new reason to avoid the activity that causes the risk.  There are plenty of arguments against those activities, of course, and those downsides must be balanced against the advantages.  Not surprisingly, the news acknowledged this for cosmetic surgery, but was steadfast in avoiding any mention of why people choose to smoke.  The image of a woman with a cigarette used to be considered sexy, but this was changed as a result of a social engineering campaign.  Perhaps if anti-obesity campaigns decide to try to create a similar backlash against double-D-cups being considered sexy, future stories about minor health risks from breast implants will be spun as definitive reasons why we should stamp out that practice, regardless of individual preferences.

I was hoping that President Obama would give me something good to write about today, but there was no mention of public health (only a bit about medical financing) and pretty much no reference to science (vague calls to improve America’s competitiveness, education, and immigration policy do not count).  But since I do not have much time to blog today, I will just write a bit about what he did say.

The one claim about public health that I noticed was wrong, that wind energy (implicitly: wind energy using our current technologies) is “clean”.  He did not make a big deal about the claim, and obviously he personally does not have time to know anything about it, so I will not harp on it.  But I wonder why no one in his administration has not figured out that it might be a good idea to not be too closely associated with that particular technology.  Even someone who insists on believing, against all the evidence, that the current industrial wind turbines do not cause serious health problems for local residents, create aesthetic damage, lower property values, and tear apart communities, surely they must realize that a lot of us are of the studied opinion that they do cause these problems.  Oh, and they are very inefficient (read: expensive and do not provide the reliable generation that the power grid needs.)   (If you are curious, there is a lot written about it; start here.)

Thus, we have to wonder why his energy advisors, who must know about the controversy, are letting him be directly associated with the issue.  It is not like tax policy, the wars, or even abortion rights, where it is difficult to avoid taking a stand; it is easy to just never mention it.  It is difficult to believe that anyone is a strong enough proponent that this would win him votes, but I know a lot of people who are strong enough opponents to consider it a voting issue.  Perhaps this is an example of people thinking they understand an issue because they only listened to the proponents of a particular belief.  Let’s see… this is day 26 of Unhealthful News, so I have probably offered more than 10 previous examples of someone making the same error, and will probably provide more than 100 more before the year is over.

More relevant to scientific analysis of health, though you probably would not realize it, is that Obama pledged to end the terrible Bush education policy called “No Child Left Behind” (NCLB).  That Bush administration policy imposed brainless standardized tests and other restrictions on the nation’s school systems, resulting in years where millions of children spent enormous amounts of their time drilling to do better on the test rather than actually learning.  The policy was widely condemned as terrible for the education of the kids, insulting to teachers’ status as trained professionals, and even corrupt (cronies of those who put it in place, including one of Bush’s brothers, were suppliers of the test-related materials to the schools).

The bit that makes this a health science story (other than the fact that focusing teaching on what can be included on a standardized test pretty much ensures that no one will learn to think scientifically) is that many proponents sowed confusion by insisting that NCLB was better because it followed a “scientific medical model”.  It was a complete misrepresentation of how health science really works, but few of the opponents of the policy had the expertise to argue this point.  (I toyed with writing some papers to help out with this, but never managed to organize the necessary collaboration.) 

It is not entirely clear whether the proponents who were using this rhetoric knew that they were misleading people or whether they actually thought they understood how health science is done.  I am guessing that they mostly committed the standard intellectual crime of hearing some claim that they vaguely understand and translating that into definitive (false) statements.  Other examples include things like the first topic of this post, and my personal favorite, “we need to run this university more like a business.”  The latter is quite similar to the “scientific medical model” rhetoric, since it usually comes from someone who either understands almost nothing about running a business or almost nothing about what a university is (first, we lay off everyone at all the unprofitable departments, like liberal arts; then, we cut back needless frills like student community building, seminars, and non-contract research; then we abandon rules that might impede our marketing efforts and IP, like free and open inquiry – hmm, come to think of it….)

The mythical “scientific medical model” that the NCLB proponents invoked was that only randomized trials are informative.  Since that has been the theme for much of January (I will write less about it in the future), I will not add to what I have already written about how wrong that is in general.  It was a wonderfully convenient claim for NCLB proponents because only very rigid interventions that anyone can do, like imposing simple uncreative classroom methods, are amenable to trials.  Moreover, trials tend to be very simplistic research and require a simple endpoint – like the scores on a standardized test.  The observational research, which can examine the value of various teaching methods that cannot be easily imposed as part of an experiment, is far more difficult to do, but has the advantage that we can try to assess what we actually care about.

Funny how most everyone who pretends to think that only RCTs are informative are those who stand to profit from either doing the RCTs or claiming that the lack of them means we have no evidence.  Going back to the first example, the consultants hired by the wind power industry are fond of trying to mislead people into believing that there is “no scientific evidence” of health effects, when what they are really pointing out is that the evidence has not been published in journals.  Even this is not entirely true, but it is true that the majority of the evidence we have takes the form of adverse event reports of specific problems.  But within another year, I expect there will be a fair bit of evidence published in journals, and at that point I expect the industry consultants to start claiming “we cannot really know anything because there are no randomized trials” (indeed, I went up against someone who was claiming that in one hearing already).

This ignorance (or pretend ignorance in the case of many of those profiting from it) is indeed a medical model.  For decades physicians drew bad conclusions as a result of conducting very bad observational research.  The solution was to teach them that they should do (or only trust) randomized trials to overcome the problems of their bad observational research (and, occasionally, problems of good observational research).  Many of them mis-learned the lesson (the problem is not observational research is not useful in general, just that physicians were really bad at it and, for some areas of inquiry like medical treatments, trials are almost always better) and somehow their misunderstanding spilled over to other non-scientists. 

The result is indeed model medical behavior: someone having the kind of practiced arrogance that makes him certain about everything, no matter how little he knows and how many mistakes he and his colleagues have made before.  Not too different from the political model of macroeconomics right now – I kind of shrugged when Obama made the mistake about wind power, but I yelled at the television when he got things so wrong about what economic policy we should pursue (and was not at all surprised when the Republicans responding to him took these same errors a lot further).  But others are much more expert at explaining those points, so I will leave it to them.

In a column this morning, Columbia University medicine professor Richard Sloan declares that there is absolutely no evidence to support the widely held belief that having the right mindset or a “fighting spirit” can benefit your health.  The trouble with having a burning urge to debunk is that it is sometimes hard to know when to stop.

Most of what Sloan has to say is reasonable.  As much as someone might like to think that having a positive attitude can slow the growth of cancer cells or even bolster our immune system, the evidence shows that the effect is minimal.  The belief that there is a strong effect is easily attributable to selective memory and reporting.  No one ever says, “he did not have a spontaneous remission because he is such a lazy heathen.”  Sloan also recounts stories of a few of the many movements and traditions that have put far too much faith in the power of thinking and belief (strategically avoiding mentioning any currently influential religion).

But his thesis statement is simply wrong.  He claims: 

But there’s no evidence to back up the idea that an upbeat attitude can prevent any illness or help someone recover from one more readily.

This is certainly not true for the many illnesses that have psychological distress at their core.  For depression and the other psychological diseases that arguably account for more of the total disease burden than physical conditions, Sloan’s claim comes close to being wrong by definition.  Those conditions are not, of course, merely attitude, but many of them are obviously closely tied to it.  So perhaps Sloan had in mind the caveat “any physical illness” but was just so caught up in his point that he forgot that he needed to clarify. 

But many physical diseases also have causes in mood, attitude, or mindset.  He tries to dismiss this by pointing out old myths about breast cancer being caused by sexual inhibition and other bad attitudes (but when is it not possible to pull some absurd believe from the dark ages of medicine – by which I mean now or any earlier point in time – to illustrate that a particular pattern of belief led to some absurd claims?).  He also notes the belief that stomach ulcers are caused by “unresolved fear and resentment” (I would have gone with “stress and anger”), which was rather less absurd in its day.  But he includes in that list hypertension being caused by “inability to deal with hostile impulses”, which is not a very strong argument.  While we now know that stomach ulcers are caused by H. pylori infection, it is not entirely clear that stress has no effect.  As for hypertension, while most causes have little to do with our thought patterns, some of them do.

It is on the recovery side that this blanket dismissal falls down completely.  Sloan uses the news about Gabrielle Giffords’s recovering from the effects of our American culture of political violence as the hook to publish this column.  (Yes, I know, it is guns that shoot people.  Or violence-prone individuals.  It is not because of the cultural norms that make guns common, or the rhetoric that triggers the inclination some people have to pick up a gun and shoot people.  Oh, wait, yes it is.  In the spirit of yesterday’s post, all of these are the cause of her injury.  Come to think of it, this is a much simpler example than I used yesterday.)

Anyway, Giffords’s case is a particularly bad choice for Sloan.  It is true that her much cited “fighting spirit” probably did not help her survive the bleeding and brain swelling that could have killed her.  But recovery from a traumatic brain injury can depend hugely on someone’s spirit or mindset.  Re-learning, in middle age (when we do not have the brain plasticity of young children) how to do thing things that the missing bits of brain used to control, dealing with frustration and a sense of loss, and overcoming the mood disorders that often result from such injuries require an enormous amount of work.  Such work is aided by having a fighting spirit.  I have personally witnessed the recovery from severe brain injury of a young highly-driven person who fought back hard and an older person who made some efforts but just did not have as much spirit.  The differences were enormous.  Obviously my two observations do not constitute a very good study, and I understand that many myths come from inadequate studies like this.  But I am not arguing the statistics; this is the type of causal pattern that you can observe without statistics.  Having less fighting spirit can obviously cause someone to not push hard enough through the difficult effort that improves recovery.

I can provide even more direct insight.  My shoulder was injured to the point that last summer I could not use my arm very effectively (we are talking not being able to wear most shirts due to loss of mobility).  After getting treatment and learning the right strategy for recovery, I was stoked to fight back, and endured serious pain to recover about 80% of what I had lost.  But when the point of diminishing returns coincided with other events that left me with rather less fighting spirit, I stopped pushing hard enough to finish the recovery and, surprise!, stopped recovering.  (Though failing to recover from an injury that ends one’s rock climbing career might actually result in better health in the long run.  Causation is complicated.)

I understand that Sloan was probably thinking something like “a fighting spirit will not fix blood vessels or make chemotherapy agents work better” when he went overboard and made a much broader statement.  But even then, the claim is not entirely correct.  Even if fighting spirit, praying, anger, resignation, and boredom have no effect on a treatment, complete resignation can cause someone to give up on the medical efforts and just die.

As a broader lesson, this is a case of how easy it is to deny any broad phenomenon by picking its weakest claims and pointing out that they are wrong.  This is the counterpart of advocates of a theory cherrypicking evidence that seems to support it.  Instead of addressing the evidence about how willpower affects recovery from serious trauma, it is possible to observe that many people believe that cancer can be driven to remission by joyous prayer.  It is then easy to point out that studies have failed to show that this is true.  That does not mean that every claim of attitude affecting health is wrong, of course, but it is easy to write an essay that implies that it does. 

The lesson, then is of weak science and powerful rhetoric.  The fact that someone can attack weak claims and thereby get away with publishing statements that any editor or reader should realize are overly general (who among us has not observed someone taking actions to recover from a serious injury or illness make better progress when in a good mood?) is a good cautionary tale:  If someone wants to “debunk” what you are trying to support, there is a good chance they will find the least defensible claim that you make and use it to imply that the entire category of claims is wrong (a little hint to my colleagues in THR).