But here's where healthcare reformers run up against an awkward reality: Preventing health problems doesn't necessarily save money. Sure, eating sensibly is free, and so is walking or jogging. But many of the screening tests and other services aimed at early detection of medical conditions cast a large—and therefore expensive—net in order to identify the relatively small number of people who actually have breast cancer, for example, or HIV. The frequency of screening is also a factor; repeated screening may detect more problems earlier, but there's a trade-off in cost.
Researchers put a fair amount of energy into trying to figure out which preventive measures provide the most benefit for the money. One way they evaluate the cost-effectiveness of a particular preventive service is by determining the cost per year of life saved. Breast cancer screening, for example, costs $48,000 per year of life saved, according to estimates from the Partnership for Prevention, a policy and advocacy group. In other words, you have to do $48,000 worth of preventive mammography screening in order to extend one woman's life for one year. Colorectal cancer screening is more cost-efficient; it costs only $12,000 to extend a life for a year.
A few preventive services actually do save money. These include clinicians discussing taking a daily aspirin to prevent heart disease with men over 40 and postmenopausal women; pneumococcal vaccination in adults over 65; and smoking cessation counseling. One of the very best buys is childhood immunization, which prevents children from developing a whole host of diseases for very little cost.
But cost is hardly the only consideration. "The reason to do prevention is to save lives, not to save money," says Ned Calonge, chairperson of the U.S. Preventive Services Task Force. The task force is a congressionally mandated, 16-member panel that reviews the scientific research supporting some 200 preventive services and makes recommendations about which services people should get and when. Members calculate the net benefit of a service—the improvement in morbidity or mortality minus the potential harm—and use that information to determine that cervical cancer screening, for example, should be strongly recommended for women who have been sexually active. Many providers and insurers rely on the task force's recommendations.
If everyone followed the task force's advice, about half of all deaths each year could be prevented, at least temporarily, according to Calonge (no one cheats death forever, of course). But in general, only a fraction of people who should get a particular preventive service do so. Fewer than half of adults age 50 or older have had a colonoscopy or other screening for colorectal cancer, for example, and just over a third of adults in the same age group get an annual flu shot. If 90 percent of people in those two groups got just those two preventive services, 26,000 lives would be saved annually, the Partnership for Prevention estimates.
Experts generally agree that certain screening tests improve the overall health of the population; blood pressure testing is one example. But there's controversy over the value of other tests. Screening can, paradoxically, "make the population less healthy because it leads to so many more diagnoses and to overtreatment," says H. Gilbert Welch, a professor of medicine at Dartmouth Medical School and author of Should I Be Tested for Cancer?: Maybe Not and Here's Why. He cites prostate cancer screening as an example. Since the prostate specific antigen test was introduced in the late 1980s, over a million men have been diagnosed with prostate cancer who otherwise would not have been, Welch says, and up to half suffer serious treatment-related side effects like impotence and incontinence. Prostate cancer deaths have declined since the introduction of the PSA test, but factors other than more aggressive diagnosis—improved treatments, for example—might be responsible for the decline. "We still don't know whether this test helps reduce prostate cancer mortality," Welch says.