Given these possibilities, health policy makers must weigh the risk of finding—and treating—a cancer that would never hurt you against the risk of missing one that could take your life. For instance, there’s no doubt that the Pap smear has prevented an epidemic of deaths from cervical cancer over the past 50 years, but it also creates many false alarms that needlessly subject women to painful follow-up tests, says North Carolina’s Harris. According to an analysis published in the American Journal of Clinical Pathology, screening every three years instead of annually provides 90 percent of the benefits while reducing the harm by roughly 33 percent. That’s why the current guidelines from the American Cancer Society and other medical organizations state that women ages 30 to 65 need a Pap test every three years, or every five years if they also get an HPV test (for a virus associated with cervical cancer).
Despite this professional consensus, a survey published earlier this year in the American Journal of Preventive Medicine found that most of the 366 obstetrician-gynecologists interviewed continue to recommend annual Pap tests. “Some physicians may have a financial interest in having women come back for yearly Pap tests because it gets them in the door,” says Gibson.
Why we’re being overdiagnosed
Our rush to detect and then treat diseases before they produce symptoms has led to a proliferation of “prediseases,” such as prehypertension, prediabetes and preosteoporosis, that turn healthy people into patients, says the BMJ’s Godlee. The definitions of normal and abnormal are generally created by panels of doctors—but they are sometimes influenced, Godlee says, by pharmaceutical companies that hope to create a wider market for their drugs by expanding the definition of illness to include the worried well.
“By some counts, half of all white postmenopausal women have preosteoporosis. This arbitrary cutoff point pulls in large numbers of women at very low risk of fracture,” says Godlee. “For the drug companies, it’s a gold mine.”
Doctors want to help their patients prevent serious health problems, but in some cases, this urge to do more exposes patients to risks without much potential benefit. A study reported this year in JAMA Internal Medicine asked more than 200 physicians to read vignettes describing six fictitious patients and decide whether they’d prescribe each patient a cholesterol-lowering statin drug. About 88 percent of the doctors said they would prescribe statins, which can cause serious side effects such as muscle damage, diabetes and liver damage, to patients unlikely to gain any benefits.
Physicians have been taught that delivering care means doing everything they can, which often biases them toward doing something. “It’s always much harder to watch and wait than it is to test, because testing relieves everyone’s anxiety—whether or not it makes you better,” says Lisa Schwartz, MD, a professor at Dartmouth Medical School and coauthor of Overdiagnosed.
Another major culprit in overdiagnosis is the way we pay for health care, says Gibson. “Hospitals and doctors are paid more for doing more,” she says. “No one makes money when they decide to watch and wait.” Sometimes doctors have financial reasons for favoring drug treatment or a medical device. ProPublica’s “Dollars for Docs” investigation has documented pharmaceutical incentive programs that give doctors generous monetary rewards for prescribing a company’s drugs.
And then there is “defensive medicine,” aka doctors’ fear of being sued for malpractice if they don’t do everything they possibly could. “You’re sued for not doing something, but you’re rarely sued for doing too much,” Schwartz says. In a survey published in the -Archives of Internal Medicine in 2011, 76 percent of the physicians surveyed said malpractice fears drive doctors to treat their patients too aggressively.