Map of life expectancy at birth from Global Education Project.

Monday, June 01, 2009

Primum no Nocere?

We've all learned that "First do no harm" is supposed to be a motto of the medical profession -- I believe the saying is attributed to Hippocrates. But the truth is, any physician who tried to live by that model would be paralyzed, unable to practice. I would put the harms done by medicine in various categories, some unavoidable, some ameliorable or reducible, but harm there will always be. This is why doing too much, medically, is more than just a waste of money. Here is one schema for thinking about iatrogenic -- medically induced -- disease and injury. There are not generally bright lines between these categories.

1) Medical intervention is inherently risky: With exceptions -- basically in cases where a person's death is imminent without intervention -- just about everything doctors do represents a tradeoff between potential benefits and potential harms. In many cases, it's not even a mere chance of harm that's in question: surgery is painful 100% of the time, temporarily incapacitating, and in the case of relatively major surgery may require more than a year for real recovery and leave predictable permanent deficits. Some drugs don't just have a risk of side effects, there are adverse effects that they cause predictably.

People can make the choices that seem best to them in those circumstance, but even more pervasively, medical treatment is a roll of the dice. You can decide that the really bad outcome is snake eyes and hence unlikely, but it is possible. Doctors are always thinking probabilistically: (potential benefit of intervention * probability of benefit)-(potential harm of intervention * probability of harm) > 0? Let's do it. Of course you have to put a value on the potential harm and benefit and there are likely several of them with differing probabilities and importance. That goes for diagnostic procedures as well, by the way. "Let's do it just to make sure" seems hard to argue with, except that it could hurt you in the process.

Unfortunately, doctors have a bias toward action. As Atul Gawande shows in the essay, this may be due to financial incentive, but even without the call of the greenback, doctors like to do stuff. Alas, more is not better. It's always tempting when confronted with an individual decision to think, "Let's do all we can for this person," it's just human nature. Sometimes doing less, or even nothing, is the best choice, but it's the hardest one to make.

2) The nosocomial problem: This could be viewed as a sub-category of (1), but it's sufficiently pervasive and distinctive to merit a paragraph. Hospitals are very dangerous places. They are filled with sick, debilitated people whose immune systems are not up to par, who have extra holes in them with tubes going in and out of said holes as well as some of their natural orifices, which means they are pathogen heaven, no matter how hard they work at keeping everything clean. (Which, by the way, is not hard enough. The cleaners make close to minimum wage, they don't even get health insurance, they get no respect, and they consequently are not particularly interested in sterilizing every square milimeter of urine stained tile. But I digress.)

In an effort to control what would otherwise be plague central, the doctors act like feedlot operators and saturate the place with antibiotics. Alas, bacteria have awesome powers of evolution. Not only can mutations move through populations of the same species, but they can swap genes between species. They can even pick up DNA from dead cells. Hospitals have given us methycyllin resistant Staphylococcus aurea (MSRA), and multi-drug resistance Clostridium difficile, among other gifts. Go into the hospital, and in addition to the distinct risk of having MSRA eat your face and C. difficile destroy your intestines, you are at risk to wind up with a bladder infection, wound infection, pneumonia, and God knows what else. In other words, you don't want to go there.

3) Screwups: Yup, health care providers make flat out mistakes: mixing up patients, amputating the wrong leg, putting the wrong pills in the bottle, using treatments that have been scientifically discredited, you name it.

4) Psychological and cultural iatrogenesis: There is something to be said for just accepting things. While the influenza hysteria mongers were provoking people to ask, "Are we all going to die?" I was waiting here quietly with the comforting answer: Yes. We cannot, for example, conquer cancer, because it is an inevitable feature of senescence: the mechanisms that regulate cell division and specialization wear out over time. If we control one cancer, another will come along. Nor can we expect to live our lives free of pain, or sadness, or some degree of functional limitation. There is a great deal to be said for learning how to live with the ills of the flesh and mind, coping with them, working around them, and keeping on going. This gets into a philosphical and moral thicket of some density, which I will avoid for today, but just remember that it's out there.

So, the point of all this is that the benefits of medical intervention stop outweighing the harms at a point well short of how far we tend to go here in the U.S. Rather than being terrified of "rationing" and having somebody tell us that we can't have all the PET scans and joint scrapings we think we want, we really ought to demand -- affirmatively demand -- to receive less. We'll be a lot better off, and not only because we'll have more money left in our pockets.


roger said...

could we require hospitals to put up this large notice at the entrance:

"janitorial staff are poorly paid and have no health insurance"

probably not.

also. "using treatments that have been scientifically discredited" seems to me to be categorically different from the other mistakes you list.

Cervantes said...

Well Rog, yes and no. The fact is that a good portion, probably most, of what doctors do is not based on evidence, but either on tradition -- we've always done it this way, I've tried it and it seems to work -- or of course on marketing by drug companies.

When treatments are discredited, it takes a long time for doctors to get the news. They just don't keep up with the literature, and there is very little effort made to push it out to them. It's a real problem, that people talk about all the time, just not very often where lay people can overhear.

Bix said...

I hear you.

Is it left to the consumer then, to weigh the costs and benefits of, say, a statin, a proton-pump inhibitor, a course of antibiotics or antidepressants, a CT scan? Just talking out loud.

Many people I know would go along with this advice if their doc advised it (and insurance covered it). They may have a quiet voice inside questioning it, but whatever crisis brought them to the doc's doorstep seems to fuel their belief in the doc's authority ... or something. "It's not good for most people, but my situation is an exception." That kind of thing.

Anyway, great, thoughtful post. Enjoy reading.