An ounce of prevention is worth … only an ounce of cure

The conventional wisdom about healthcare costs is that preventive medicine saves money. Indeed, during the recent primary and general election campaigns, many candidates relied on the assumed savings from preventive medicine to either control healthcare costs or to provide the money to extend healthcare coverage.

Unfortunately, the claims of cost savings from preventive medicine have been vastly overstated. The existing research shows that most preventive measures do not save money compared to treatment and quite a few actually cost more money than treating the illness in question. A recent article in the New England Journal of Medicine lays out the disappointing evidence.

 Does Preventive Care Save Money? Health Economics and the Presidential Candidates, was published in June and evaluated the candidates’ claims about cost saving. The paper represents a collaboration between two professors of medicine and a professor of health policy and management. First, they frame the problem:

Sweeping statements about the cost-saving potential of prevention, however, are overreaching. Studies have concluded that preventing illness can in some cases save money but in other cases can add to health care costs. For example, screening costs will exceed the savings from avoided treatment in cases in which only a very small fraction of the population would have become ill in the absence of preventive measures. Preventive measures that do not save money may or may not represent cost-effective care (i.e., good value for the resources expended). Whether any preventive measure saves money or is a reasonable investment despite adding to costs depends entirely on the particular intervention and the specific population in question. For example, drugs used to treat high cholesterol yield much greater value for the money if the targeted population is at high risk for coronary heart disease, and the efficiency of cancer screening can depend heavily on both the frequency of the screening and the level of cancer risk in the screened population.

The authors reviewed the literature on preventive medicine and cost savings. They identified 599 studies across all areas of medicine. For their analysis, the authors compared the cost effectiveness of prevention to the cost effectiveness of treatment as ratio of cost to QALYs. A QALY is a quality-adjusted-life year. A low ratio is desirable because that indicates that a particular measure is inexpensive compared to the QALYs gained. In contrast, a high ratio indicates that it takes a great deal of money to achieve a relatively minor benefit.

What they found directly contradicts the conventional wisdom. Analysis of the data in the 599 studies showed that the costs of prevention are roughly similar to the costs of treating the disease in question. The authors explain:

… the distributions of cost-effectiveness ratios for preventive measures and treatments are very similar — in other words, opportunities for efficient investment in health care programs are roughly equal for prevention and treatment, at least as reflected in the literature we reviewed. Moreover, both distributions span the full range of cost effectiveness…

… Some preventive measures save money, while others do not, although they may still be worthwhile because they confer substantial health benefits relative to their cost. In contrast, some preventive measures are expensive given the health benefits they confer. In general, whether a particular preventive measure represents good value or poor value depends on factors such as the population targeted, with measures targeting higher-risk populations typically being the most efficient…

The article has several important implications. First, while preventive medicine may be desirable because it prevents illness in some people, it does not save money because screening and other preventive measures cost the same or more than treatment.

Second, all preventive medicine is not created equal. Some preventive measures, like vaccination, are extremely cost effective. Others such as intensive anti-tobacco education for middle schoolers are extremely cost ineffective, with a cost to QALY ratio $23,000/QALY, according to the paper.

Third, restricting preventive measures to at risk populations is much more cost effective than applying preventive measures to the entire population. This is in keeping with what we know about screening tests. They are much more accurate in high risk populations than in the population at large.

This does not mean that we should abandon preventive care. We should continue to provide anti-retroviral prophylaxis to HIV positive patients in order to delay the development of full blown AIDS. Such a policy is ethically mandated, even though it costs approximately $29,000 per QALY.

Preventive medicine is beneficial because it prevents disease, but the evidence shows that it does not save money, regardless of what political candidates and others may claim.