When an ounce of prevention is worth an ounce of cure

The greatest longevity advances of the past century came from prevention, broadly defined. In the first half of the 20th century, centralized heat, water and sanitation added decades to the average American lifespan.

After World War II, mass vaccination campaigns and public health crusades around car safety and smoking helped reduce infant mortality, trauma deaths and cancer incidence.

Preventive medicine also played an important role in reducing disease mortality and morbidity. The discovery that high blood pressure and elevated cholesterol were associated with heart disease led to drug interventions to manage those conditions. We now know that simply taking a low-dose aspirin daily can reduce the incidence of heart attacks and strokes.

The search for new public health measures that can improve overall population health goes on. Food companies are removing the transfats that clog arteries and reducing the salt and sugar content of processed foods.

Scientists have identified numerous man-made environmental contaminants that increase the incidence of asthma, cancer and heart disease. While removing or limiting them in the environment undoubtedly saves lives, efforts to regulate pollutants usually trigger heated debates over the relative costs and benefits. Indeed, it is enshrined in law that the government must conduct a cost-benefit analysis before regulators take any action.

Preventive medicine has not received the same level of scrutiny until the past decade.

Much of the debate focuses on cancer screening. Screening for cancer is intrinsically alluring because once one gets cancer—whether due to bad habits, bad environmental exposures, bad genes or bad luck—the best chance of survival comes from catching and treating the disease early.

Yet each of the four leading cancers—lung, colon, breast and prostate—now have screening tests that have become embroiled in controversy. Critics either question their medical benefits or suggest their costs, which include side effects associated with false positive tests, far outweigh their benefits. Should an older man continue to get PSA tests? Should smokers get annual CT scans for lung cancer? Are periodic colonoscopies superior to an annual stool test?

Last week, another study called into question routine mammograms for women under 60. A retrospective study of nearly 90,000 Canadian women showed no difference in breast cancer mortality between those who had regular mammograms over 25 years and those who didn't. What the screened group did get was more diagnoses of cancer, subjecting about 1 in every 424 women who get mammograms to unnecessary follow-up tests and procedures.

The study was immediately attacked by radiologists, who claimed newer machines are more accurate, and patient advocates, who called for better tests. Even so, the response was far more subdued than the brouhaha that greeted the U.S. Preventive Services Task Force's 2009 recommendations, which proposed women under 50 forget about routine mammograms and women up to age 75 get them only every other year.

Given the uproar, it wasn't surprising a 2012 study showed those recommendations had zero effect on physician practice or patient preference. But can healthcare providers continue to be cavalier about the mounting evidence that some preventive medicine measures aren't generating clear-cut benefits or that their physical, emotional and monetary costs far outweigh their benefits?

Most preventive medicine measures cost more than they save through reducing other healthcare costs. One-time colonoscopies for 60- to 64-year-olds reduce overall healthcare spending. But screening the same group for diabetes if they don't have hypertension adds nearly $600,000 in healthcare costs for every year of additional life achieved for those identified early with the disease.

In an era when healthcare systems are under intense pressure to reduce spending on unnecessary care, providers need to know the true value of preventive measures and whether they are being targeted at the right populations.

In a fee-for-service reimbursement system, some physicians will always push back against such thinking. Many patients—including the well-insured worried well—will claim they are being denied needed care.

That puts the onus on those responsible for keeping costs in check to conduct careful evaluations of the underlying evidence. They should pay close attention to recommendations from the USPSTF, whose independent panels determine which preventive measures must be offered at no cost in health plans sold on exchanges. And they should begin offering decision aids to patients and beneficiaries so they understand the true risks and rewards of preventive medicine.

Follow Merrill Goozner on Twitter: @MHgoozner