Biotech Values

[DewDiligence]

Campaign Myth: Prevention as Cure-All

http://www.nytimes.com/2008/10/07/health/views/07essa.html

›October 7, 2008
By H. GILBERT WELCH, M.D

In a presidential campaign that promises straight talk and no gimmicks, why do both candidates champion one of medical care’s most pervasive myths?

The myth is that like magic, preventive medicine will simultaneously reduce costs and improve health.

Senator John McCain argues that “the best care is preventative care,” and his health care reform plan claims that “by emphasizing prevention” and other measures “we can reduce health care costs.” Senator Barack Obama’s plan says, “Simply put, in the absence of a radical shift towards prevention and public health, we will not be successful in containing medical costs or improving the health of the American people.”

It may sound like common sense. But it is still a myth.

The term “preventive medicine” no longer means what it used to: keeping people well by promoting healthy habits, like exercising, eating a balanced diet and not smoking. To their credit, both candidates ardently support that approach.

But the medical model for prevention has become less about health promotion and more about early diagnosis. Both candidates appear to have bought into it: Mr. Obama encourages annual checkups and screening, Mr. McCain early testing and screening.

It boils down to encouraging the well to have themselves tested to make sure they are not sick. And that approach doesn’t save money; it costs money.

Increasing the amount of testing for an ever-expanding list of problems always identifies many more people as having disease and still more as being “at risk.” Screening for heart disease, problems in major blood vessels and a variety of cancers has led to millions of diagnoses of these diseases in people who would never have become sick.

Likewise, recent expansions in the definitions of diabetes, high cholesterol and osteoporosis defined millions more as suddenly needing therapy. A new definition of “abnormal bone density,” for example, turned 6.8 million American women into osteoporosis patients literally overnight.

These interventions do prevent advanced illness in some patients, but relatively few. Any savings from preventing those cases is dwarfed by the cost of intervening early in millions of additional patients. No wonder pharmaceutical companies and medical centers see preventive medicine as a great way to turn people into patients — and paying customers.

If preventive medicine were effective in improving the nation’s health, it might warrant these added expenditures. But you can’t assume it is. Early diagnosis may help some, but it undoubtedly leads others to be treated for “diseases” that would never have bothered them. That’s called over-diagnosis.

Early screening is like the “check engine” light in your car. It can alert you to problems that need to be fixed, but too often it picks up trivial abnormalities that don’t affect performance, like one sensor’s recognizing that another sensor isn’t sensing.

And if we look hard enough, we’ll probably find out that one of your check-engine lights is on.

Over-diagnosis occurs even among what were once considered uniformly deadly diseases.

When it comes to cancer, for example, there is a very broad spectrum of diseases. Some kill rapidly, some progress slowly, and some do not progress at all.

That is why some doctors recommend “watchful waiting” for men with early prostate cancer: most cases never prove fatal. It was because of concerns about over-diagnosis that the United States Preventive Services Task Force recently recommended against prostate cancer screening in men over 75. Similar phenomena have been documented in early-stage breast cancer, lung cancer and melanoma.

Most diseases exist along a similar spectrum. Even without treatment, most cases of aortic aneurysm never result in a fatal rupture, most patients with osteoporosis won’t fracture their hip, and most people with diabetes won’t lose a limb.

It’s hard to ignore a “check-engine” light. Some mechanics reset them and see if they come on again, but often they lead you to a repair. And you may have had the unfortunate experience that a repair makes matters worse.

If so, you have some feel for the problem of over-diagnosis. Almost everybody with a diagnosis undergoes treatment. And all of our treatments have some harms. From 1 to 5 percent of patients die after major surgery, and as we are all increasingly aware, prescription medicines carry real risks. Recent experiences with hormone replacement (breast cancer) and Vioxx (heart attacks) are potent reminders that our “best” new treatments may harbor unpleasant surprises.

For those who are ill, the potential benefits typically overwhelm the potential harms. But the calculus is different for those recruited to consume preventive medicine: those who are well. They are the ones at risk for over-diagnosis — and over-diagnosed patients can’t benefit from prevention, because there is nothing to prevent. Instead, they can only be harmed.

Both presidential candidates need to challenge the conventional wisdom about preventive medicine. They should ask whether the path to a healthy society is the one that turns those who are well into patients anxious about their future. They should inquire whether more diagnoses will lead to more unnecessary treatment. And they should question whether suggestions that preventive medicine will save money — and fix the health care system — pass the tests of evidence and logic.‹