ACP Internist Blog


Monday, October 22, 2018

Modern medicine and maladies of evidence

I won't name any names, but I just read that a former science editor at a major, global publication has concluded that science advocacy is boring, and that she would now prefer to “slaughter the sacred cows” of conviction. Leaving aside the somewhat brutal image, and the potential innocence and genuine sacredness of the cows in question, we may simply note that acquiring conviction born of science generally takes years, even decades. Disparaging it just takes a news cycle, innuendo, and a bit of click-bait.

If we translate this ominous declaration, it readily becomes: “Reminding people what is actually true (e.g., climate change) in the hope they might finally, actually do something about it is repetitive and boring. So, let's tell them the titillating lies they want to hear instead.”

Let us pause on that note and pay our respects to the law of unintended consequences. The industrial revolution was not intended to produce epidemic rickets, or presage the inevitability of anthropogenic climate change- but it did. The advent of the Internet was not intended to make cyber-captives and/or addicts of us all, but it did. The burgeoning of social media platforms was not intended to undermine our relationship to truth (or democracy), but it has (might). All hail the law of unintended consequences; we ignore it at our peril.

The laudable objectives of evidence-based medicine were not intended to turn the subtleties of methodology into a cudgel wielded by one faction in aggression against counterparts, repudiate the merits and essential role of sense, or undermine the very concept of expertise. But alas, in this land of the law of unintended consequences, they have done just that. The undeniable merits of randomized controlled trials (RCTs) have been corrupted from the power to inform, into a tendency to tyrannize.

I will make the case preferentially within my own purview, lifestyle medicine and nutrition. But it pertains as fully to cancer screening and lipid lowering, immunization and genomics. Wherever medical news incites passions, a contagion of unintended consequences finds vulnerable hosts. If ever we are to overcome these maladies of our own, inadvertent devising, we must first understand them.

1) One method to rule them all.

A hammer is an excellent tool; every carpenter needs one. But it makes a very poor saw, a lousy screw driver, and an utterly useless router. It's a great tool, but it only does what it does.

The RCT is just the same, as fundamental to the advance of medical understanding as a hammer (or nail gun) is to every carpentry project. But it only does what it does. What does it do? Many of those who shout loudest about its episodic absence seem to have no idea.

For starters, RCTs only ever answer the questions that are posed; this is true across all methods of science. No method can produce useful answers to vapid questions; no quantity of science can redeem senselessness. Among the tyrannies and tirades attaching themselves to evidence these days is the notion that science can operate independently of sense; it cannot. Sense is the incubator of good questions; science then follows to pursue answers not already on obvious display.

The RCT is a robust tool with a number of strengths, almost all related to confidence about the attribution of X (an effect) to Y (a cause). Randomization is not a panacea of any kind, but offers the promise of controlling for confounders both known and unknown, and preventing allocation bias. What are confounders and allocation bias? Feel free to Google those, but let's simply note here that everyone presuming to tell us about the primacy of RCTs should already know.

A control group accounts for non-specific, or placebo effects. Blinding forestalls the influence of many varieties of bias, ascertainment bias notable among them. Again, feel free to Google it.

RCTs have very important weaknesses, too- and especially in the lifestyle domain. Rather than belabor those here, let me just ask you a question instead: would you be willing to let someone else “randomly” assign you to a dietary/exercise/sleep pattern for the next decade or two, rather than choosing for yourself? I don't know anyone else who would be, either.

Basic science is generally the best source for insights about mechanisms of action. RCTs are vital to confidence in attribution, but generally for short-term effects in select populations. Our best insights about population-wide and longer-term effects come inevitably from observational epidemiology.

One method of science no more obviates all others than a good hammer precludes the utility of a screwdriver.

2) I heard it through the grapevine.

Hard though it may be to remember or believe, there was a time when the only people who read medical journals had subscriptions, and received them in print. These were, of course, carted around on sleighs, because the wheel had not yet been invented…

The audience for these incremental additions to the biomedical fund of knowledge included practitioners and scientists, and credentialed media outlets that would receive print copies in advance under embargo. Under such quaint and archaic circumstances, media coverage was, if not always spot on, generally competent and careful and considered.

Now, of course, medical studies- or at least snippets of them- are circulated digitally in real time. Everyone has access to them, and that is the only license required to opine. Opine people do, with or without relevant expertise. In fact, expertise is a hindrance, because experts feel obligated to read studies completely and carefully, and at least to attempt a bias-free interpretation. The highly partisan, non-expert knows no such constraints; and that much less so the true fanatic, fool, or Internet mercenary.

So, often uninformed opinion is the first wave. Any given faction can go shopping for the conclusion it already favored, find it, and amplify it. And then, when the as yet undecided or nominally impartial go shopping for information on the topic, they find a trove corroborating whatever opinion was espoused at the start of this chain reaction. Volume and vehemence are mistaken for veracity, and so these new recruits- some of them with professional credentials- embrace the new narrative. Their endorsement is then trumpeted by those who propounded their own wishful thinking at the start as further evidence that…they were right. And so, we have a mole hill of idle opinion and misinformation grown into a veritable mountain.

What makes a bit of misinformation into a mountain of misinformation? The claim that it stands on a bedrock of evidence. But nothing in that claim requires the evidence to have been interpreted expertly, accurately, or even honestly at the start.

The contention that saturated fat has been exonerated of crimes against coronary arteries, and that we should eat more meat, is just such a false narrative. The claim that sugar has been overlooked in dietary precautions of the last half century is just such a false narrative. Richly detailed historical accounts are overtly misrepresented. And so we have the imprimatur of evidence corrupted into the justification of something else entirely. We all now strive in the shadows cast by such mountains.

3) What's good for the goose … gives the gander a pass.

Challenges to the reliable interpretation of evidence don't invite caution as they should; instead, they seem inevitably to encourage a rush to judgment in the opposing direction.

Even as we are told how and why to distrust science, we are told how and why some new study is, all on its own, enough to change everything we thought we knew until this morning.

Folks, it takes less than half a wit to see that both of these cannot be true. If science tends to be less reliable than we might like, then how much less reliable is any one study, compared to the aggregation of evidence across decades? Conversely, if we can suddenly “know” the truth based on any one study dominating a news cycle, how much more so based on the full weight of evidence? If you don't trust the staggering mass of evidence regarding climate change, or evolution, or the benefits of eating more vegetables and fruits, how can you possibly trust any one study claiming something else? The answer is, you can't- unless you are simply shopping for support for the opinion you've already decided to call your own, no matter what the evidence says.

That we can't trust ALL of the evidence, but can confidently change everything we thought we knew based on some tiny fragment of evidence is inconsistent nonsense at best. At worst, it is hypocrisy. The law of unintended consequence warns us to expect the worst.

4) Even truth is judged by the company it keeps.

Imagine that partisans of Religion A have concluded that killing in the name of god is good, and right, and holy. Partisans of Religion B have concluded, conversely, that no god worth having would sanction killing in her name.

Now imagine that an independent group of secular, agnostic, and possibly atheistic ethicists takes the matter on. They follow where the precepts of their discipline, logic, precedent, and conscience lead them- and reach the conclusion that killing in the name of god is unethical. What happens next?

The Religion B congregation swoops in to claim these ethicists as their own and celebrate their righteous conclusion. Religion A adherents, however, repudiate the ethicists as hacks, note their alignment with Religion B, and dismiss their conclusion as partisan and prejudicial.

But this dismissal obviously puts the sausage-laden cart before the horse. These ethicists had no vested interest in either religion; they simply pursued the “right” conclusion. That it aligned with the views of one group rather than another was happenstance.

So, too, for nutrition- where the consensus about the merits of plant-food-predominant diets, and the science underlying that case, is massive, global, and transcends dietary preferences, academic disciplines, or any given ideology. In other words, the conclusion is non-partisan. But it happens to align, like the conclusion of our imaginary ethicists, with the views of some very partisan groups that advocate for the same, causing groups with opposing conclusions to impugn the conclusion itself as partisan.

*******

The goals of evidence-based medicine are laudable. But evidence is just means; understanding is the ends. These means, like all others, are subject to the law of unintended consequences. By mishandling the means, we corrupt the intended ends- and propagate a costly misunderstanding at the expense of common sense, common cause, and common knowledge. Until or unless we better manage the conscription of evidence into the contagions of misinformation, we are all apt to be victims of just such plagues.

db's anion gap pearls

Almost every resident has an anion gap talk. Many students learn MUDPILES – I prefer KILU (An anion gap puzzle that explains KILU). But many learners do not know these particular pearls.
1. A gap of 25 or greater generally has a discoverable cause, 30 or greater almost certain – Diagnostic Importance of an Increased Serum Anion Gap | NEJM
2. The anion gap does not accurately screen for lactic acidosis in emergency department patients, i.e. check lactic acid levels if you suspect lactic acidosis do not rely on the anion gap
3. Most patients with mildly elevated anion gaps (15-19) do not need immediate evaluation. You should use clinical judgment prior to evaluating such gaps.
4. The influence of albumin on the expected anion gap This article describes the precise formula. We use albumin times 3 as a reasonable estimate.

db is the nickname for Robert M. Centor, MD, MACP. db stands both for Dr. Bob and da boss. He is an academic general internist at the University of Alabama School of Medicine, and the former Regional Dean for the Huntsville Regional Medical Campus of UASOM. He still makes inpatient rounds regularly at the Birmingham VA and Huntsville Hospital. His current titles are Professor-Emeritus and Chair-Emeritus of the ACP Board of Regents. This post originally appeared at his blog, db's Medical Rants.
Thursday, October 18, 2018

When should your doctor say 'I'm sorry'?

For many Jewish people throughout the world, this past week provided an opportunity to reflect on one's life and to invest in one's soul. While self-examination should be an ongoing task, the Hebrew Day of Atonement is a singular opportunity to meditate deeply on this process. While this day culminates a 10-day period of intense reflection—or so it should—once again, this does not relieve us of our obligation to pursue this task on all other days.

Atonement is a tough business and I admit that I am no expert. Consider how challenging this process is.
• personal reflection.
• acknowledging personal flaws and transgressions.
• approaching those whom we have wronged to make it right.
• forgiving those who seek our pardon with grace.
• committing not to repeat our offenses if placed in the same circumstance again.

Sounds easy? Hardly. Changing our traits and actions are very difficult. Why do you think so many of us have the same list of New Year's resolutions every year?

But, change is possible.

Here are some actions that many in the medical profession might seek atonement for. I am judging no one here, and I admit that as I construct this list that I am not without sin.
• A diagnosis is missed because a physician was not sufficiently diligent.
• Privileged health information was inadvertently disclosed.
• A physician is habitually late and is indifferent to his patients' time.
• A doctor disparages a colleague.
• A physician fails to return phone calls from concerned patients.
• A doctor berates one of his staff who made an error.
• A doctor berates one of his staff who did not make an error.
• A doctor modifies a medical record for the wrong reasons.
• An impaired physician does not seek professional assistance.
• A physician has a lapse in his bedside manner and doesn't demonstrate the empathy the patient deserves.
• A physician thinks of his own interest over the patient's interest.

I don't ask any reader to pay any heed to this post penned by a confessed imperfect and flawed man.

This post by Michael Kirsch, MD, FACP, appeared at MD Whistleblower. Dr. Kirsch is a full time practicing physician and writer who addresses the joys and challenges of medical practice, including controversies in the doctor-patient relationship, medical ethics and measuring medical quality. When he's not writing, he's performing colonoscopies.
Monday, October 15, 2018

Big, fat, new meaning to 'Red State'

I have quipped wryly for years that the relentless rise in obesity rates would eventually exhaust Crayola's supply of colors. That's because the CDC has long tracked the rising prevalence of obesity by state using color-coded maps of the U.S.

The latest update to those maps is now hot off the presses, and shown above. Apparently, Crayola (well, whoever supplies the font colors in question, actually) hasn't run out yet. The new map from CDC shows seven states with obesity rates above 35% in red. It's not a Scorsese red; more of a Harvard red. I suppose we may as well just call it “CDC-red.” But red just the same. One can't help but wonder about subtle, cartographic political commentary.

I will defer those considerations to others, pausing here just long enough to note that obesity, public policies, politics, and poverty all do track together. The states that are now CDC-red, representing unprecedented levels of obesity, are disproportionately red in other ways, too.

If we focus, though, only on the relentless rise in obesity rates in these states, and the comparable if alternatively tinted version of that same trend in all the other states, too, we are still left with a very provocative tale, and a set of profound implications.

First, variation in obesity rates by state shows that this is much more a problem of populations than individuals. Individual humans are the same everywhere. But environments vary; economies vary; policies vary. Significant variation in obesity in response to all of these reminds us that preferential focus on will-power or personal responsibility is misguided. Homo sapiens have the same basic endowment, on average, of personal responsibility either side of a given state line. The mapping of obesity lays out in black, and white, and now red - the reminder that the choices any of us makes on a daily basis are subordinate to the choices we have. Those do vary by state: geographic, circumstantial, and experiential alike.

That perspective matters, because it reminds us we are likely only to accomplish so much (not much, really) admonishing people to make good choices in environments that peddle mostly bad ones. Sometimes, no matter one's responsibility, the best defense of the human body resides with the body politic. That's true everywhere we station lifeguards or rip tide warnings along beaches; it's true for the relentlessly rising tide of obesity as well. Sure, there's personal responsibility in the mix at both beach and buffet; but individuals need a fighting chance, rather than the snowball's chance in hell we give them now. If we treated beaches like the food supply, we would systematically obscure the reality of rip tides with “come on in, the water's fine!” signs.

This crimson tide also shows us starkly that we are not fixing the problem of epidemic obesity; we are still making it worse. This is not because the problem is so complicated; it is not. It is not for want of solutions; they are rather obvious. It is for want of will. However we may wring our hands, the power centers of our culture are perfectly happy with this status quo because they are profiting mightily from it. We carry on as if we have tried to fix obesity and failed. Let's at least be honest.

Rather than doing so, we turn instead to reprising past forays into failed, quick-fix, fad diets under new names. Even as we have illustrious medical journals telling us why we can't trust epidemiologic studies that reach sweeping conclusions about diet and health, we get epidemiologic studies in other illustrious journals reaching sweeping conclusions about diet and health, further amplified by media hyperbole. No, dairy fat is not suddenly a magical solution this week. No, the premier nutritional epidemiologists at Harvard are not peddling “carbs,” whatever exactly that would mean.

And all the while, we have somehow created a culture where alternatives to truth get to impersonate it shamelessly in broad daylight, yet speaking actual, blunt truth is politically incorrect. I am going to chance it anyway, as I am wont to do. We carry on about the challenges and complexities of epidemic obesity, noting that our efforts to date have failed to curtail it. The truth is our efforts to curtail it are vanishingly less substantive than our efforts to propagate it for profit, and we are reaping just what we have been sowing. We have thus far failed to fix epidemic obesity for the most obvious of reasons: we have never actually tried.

We tell one another we can't trust nutrition science, and then proceed to amplify junk science into wildly silly claims we certainly should not trust, and then say: “See! Told you so.” The reality is, we certainly could trust nutrition science if we interpreted it the way those actually trained to conduct it, apply it, and interpret it do. We do not detonate our understanding built up over decades, or cry “EUREKA!” with every news cycle and hyperbolic headline, and neither should anyone. But if we are substituting the term “nutrition science” for inane, dysfunctional reactions to distorted news about nutrition science- well, then, yes: we certainly can't trust THAT.

Teams keep picking the nutrient they want to revere or revile, all the while ignoring the massively more meaningful evidence about dietary patterns and their implications for the health of people and planet alike. The set of choices that represents the overlap between healthful, nourishing, palatable, ethical, and sustainable is dwindling fast.

Silly, pseudo-debates put saturated fat and sugar head-to-head as if there is just one thing wrong with the prevailing, modern diet. Excesses of both are injurious sure, but far more so is the stupidity (I warned you about blunt truth …) involved in thinking the indictment of one exonerates the other. Obesity down here? We've got plenty. Intelligent life? Not so much.

Let's put it this way: we bicker, as we have for decades, about who's found the better tree, as the entire forest burns down. By the light of that fire, rest assured that ever more states will turn … red.

David L. Katz, MD, FACP, MPH, FACPM, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care. He is a board certified specialist in both Internal Medicine, and Preventive Medicine/Public Health, and Associate Professor (adjunct) in Public Health Practice at the Yale University School of Medicine. He is the Director and founder (1998) of Yale University's Prevention Research Center; Director and founder of the Integrative Medicine Center at Griffin Hospital (2000) in Derby, Conn.; founder and president of the non-profit Turn the Tide Foundation; and formerly the Director of Medical Studies in Public Health at the Yale School of Medicine for eight years. This post originally appeared on his Linked In page.