Clinical trials Medicine Science

Impressive science failing to impress patients

One of the greatest challenges in medicine can sometimes be to convince a patient that the results of scientific and medical research apply to them, or, at the very least, to explain how such results apply. A couple of days ago, in an article the New York Times, Dr. Abigail Zuker, proposed one reason why this might be, beginning with a discussion with her mother in which she tries to convince her of the benefit of exercise, even in the elderly, a concept that her mother would have none of:

“Studies,” she says, dripping scorn. “Don’t give me studies. Look at Tee. Look at all the exercise she did. She never stopped exercising. Look what happened to her.”

End of discussion. Tee, her old friend and contemporary, took physical fitness seriously, and wound up bedbound in a nursing home, felled by osteoporosis and strokes, while my mother, who has not broken a sweat in the last 60 years, still totters around on ever-thinning pins. So much for exercise. So much for studies. So much for modern clinical medicine, based on the randomized allocation of treatment and placebo. All that beautiful science, stymied by the single, incontrovertible, inescapable image of Tee, the one who exercised but grew hunched and crippled anyway.

My first thought would be that such a reaction represents the power of anecdote over clinical data, but Dr. Zuker sees more than that. She sees it as the difference between how doctors are trained to view the world and how people untrained in medicine and science view the world, and she uses a rather interesting metaphor to convey this difference:

It is medicine’s eternal quest, these days, to sell impressive science to unimpressed patients, and it is hard to think of a group less equipped to do it than doctors. Doctors are specifically trained not to think like normal people, not to see what others see or to reason as others reason. They — er, we — come to operate in an atmosphere so thin, so heady and attenuated with the power of statistical analysis, that one might wonder whether we are really on the same planet as the patients we try to convince of our truths.

“Exercise helps the elderly.” The doctor sees, from a perch suspended somewhere up in the sky, a large football field filled with the elderly. There are thousands of them down there, all dressed in sweats and sneakers, dumbbells at their feet. Half of them are using the dumbbells, or are down on their backs, doing leg lifts. The others just stand around.

Over the years, of course, the ranks thin. The doctor watches, counts. It begins to look as if there are more exercisers left. After decades, there are definitely more exercisers. Of course, there are still a few sloths standing around (and one of them looks suspiciously like my mother). But by and large, the exercisers come to rule the field.

That is the view from on high. Down on the field, of course, the view is quite different. You are standing in a thick crowd, minding your own business, living your life, but you cannot help noting that the man over there threw his back out with all that exercise, and the woman next to you, grunting to lift her dumbbell, had a heart attack. You cannot see to the other end of the field and have no idea what is happening there. But watching all the sweating and grunting and seeing some of those exercisers disappear anyway, you decide to opt out.

It is true that interpreting the results of clinical studies and applying them to patients is entirely a matter of probabilities. From clinical studies, you can conclude that exercise will increase a person’s chance of living to a ripe old age. However, some people, either through good genes or sheer luck, manage to make their way through life without exercising and live to a ripe old age anyway. Similarly, we can say that, by and large, smoking can greatly increase your risk of heart disease, lung cancer, and premature death. But, then everyone knows someone who smoked for 70 years and died at age 85 of old age, apparently suffering few ill effects from the thousands upon thousands of cigarettes they smoked.
It’s sometimes very hard to overcome the power of anecdote and patient experience, even for such clear-cut cases. For example, take the rather common discussion of the pros and cons of breast conserving therapy (lumpectomy) versus mastectomy for breast cancer. Every surgeon who does breast surgery will get the occasional patient who demands a mastectomy for a small tumor that would be most appropriately treated with lumpectomy. In my experience, the reason almost always boils down to a bad personal experience. Often such patients had a close relative or friend who had breast cancer treated with lumpectomy and recurred. Usually, if you probe a little more closely, they will tell you the horrific tale of how the cancer ravaged this person after it recurred. They become convinced that it was because the deceased hadn’t undergone what they perceive as the more radical treatment of mastectomy that her cancer recurred. No amount of citing the nearly three decades of large studies demonstrating that five and ten year survival are the same for lumpectomy and radiation therapy as they are for mastectomy will sway them. The patient doesn’t care; she wants a mastectomy. This is even more true when you inform her that there is around an 8% chance of local recurrence with lumpectomy but that it doesn’t affect the overall survival rate. All she hears is that there is nearly a one in ten chance of the cancer coming back in her breast after a lumpectomy but a less than 1% chance of its doing so after a mastectomy. Statistics tell the doctor that her chances of long-term survival will be the same with a lumpectomy as with a mastectomy. The patient’s experience tells her otherwise. Therefore, she insists on a mastectomy, and, because it is a perfectly acceptable treatment for breast cancer and because she has the right to control what happens to her body, she usually gets it, even though usually more than one surgeon try to talk her out of it and even though she could surely have been treated for her cancer without losing her breast.

If the power of anecdote can be difficult to overcome in such clear-cut cases, imagine how hard it can be to do in cases where the decisions are not so clear cut or where the treatment only has a small benefit. One such example is whether or not to use adjuvant chemotherapy after the treatment of various cancers, where, depending upon the cancer and the stage, the increase in absolute chances of survival can range from as little as 3% to as much 20-25%, but rarely more. In the case of early stage breast cancer, the benefit is usually between 3-4%. Most patients will still opt for even this modest benefit. Consider next the case where the literature and studies are either lacking, of poor quality, or multiple and in conflict.

Dr. Zuker suggests some strategies to persuade the patient:

Good doctors learn some tricks, over the years, to let patients see what they see. It helps, sometimes, to descend part of the way down from the sky and give a smaller version of the big picture. (“Of all my patients, it’s the ones who exercise who do the best.”) Sometimes it helps to get down completely, and see what the patient sees (“Your grandmother smoked till she was 90, but you may not be so lucky.”)

But sometimes there is no convergence of views. The patient who sees only from the ground, the doctor who sees only from the sky may simply have to agree to disagree, and have the same dialogue over and over again.

Indeed. One way we in medicine can overcome this gap is to develop tests that help us predict far better than we can which patients will respond to which drugs and which patients are at higher risk for various complications.

Of course, I would point out to Dr. Zuker that it is not only patients who can fail to see the forest for the trees. Doctors sometimes fall prey to this trap as well. If, for example, we see a treatment resulting in a bad outcome in two or three patients in a row, we are just as prone as anyone to react by changing our approach, even though we know from the literature that we are using the most efficacious treatment available and that the last couple of bad outcomes were almost certainly a statistical fluke. We often can’t see the “whole picture” either, and that is one reason why it is so important for physicians to stay current on the medical literature and to be willing to reach out to their colleagues for advice.

In the end, it’s largely a matter of communication. This is one subject for which doctors are generally not well trained, either in medical school or residency, and one area that I wish I had become better at. In a sense, even now, I am still learning and still trying to improve.

By Orac

Orac is the nom de blog of a humble surgeon/scientist who has an ego just big enough to delude himself that someone, somewhere might actually give a rodent's posterior about his copious verbal meanderings, but just barely small enough to admit to himself that few probably will. That surgeon is otherwise known as David Gorski.

That this particular surgeon has chosen his nom de blog based on a rather cranky and arrogant computer shaped like a clear box of blinking lights that he originally encountered when he became a fan of a 35 year old British SF television show whose special effects were renowned for their BBC/Doctor Who-style low budget look, but whose stories nonetheless resulted in some of the best, most innovative science fiction ever televised, should tell you nearly all that you need to know about Orac. (That, and the length of the preceding sentence.)

DISCLAIMER:: The various written meanderings here are the opinions of Orac and Orac alone, written on his own time. They should never be construed as representing the opinions of any other person or entity, especially Orac's cancer center, department of surgery, medical school, or university. Also note that Orac is nonpartisan; he is more than willing to criticize the statements of anyone, regardless of of political leanings, if that anyone advocates pseudoscience or quackery. Finally, medical commentary is not to be construed in any way as medical advice.

To contact Orac: [email protected]

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