There is a significant difference between something saving money (net reduction in total expenditure) and being cost-effective (requiring less cost per outcome than something else). Sarah Kliff from the Washington Post takes on this question by discussing Louise Russell’s chapter 3 in Menzel’s and my edited text, Prevention vs. Treatment: What’s the Right Balance? Doug Kamerow also addresses this question in more layman’s terms in his new text, Dissecting American Health Care, Commentaries on Health, Policy, and Politics (RTI Press, p. 29).
The argument Kliff looks most at is related to the table Russell shows (figure 3.1) by Joshua Cohen, et. al. that appeared in the New England Journal of Medicine in 2008. According to Google Scholar this article has been cited 195 times since its publication.
It seems to me there is one problem with Cohen, et. al.’s article: it lumps together apples and oranges in its comparison. To compare all well-defined studies of prevention with all well-defined studies of treatment ends up comparing such disparate items as genetic screening for inborn errors of metabolism and surgery for elderly men with prostate cancer. On a macro basis this may be the best we can do when asking the economic question of prevention vs. treatment. But such comparisons seem besides the point when mixed together. I’d rather see comparisons of like-minded prevention and treatment. For example, how does preventive statin use compare with coronary artery bypass surgery? Or more broadly, how does screening and reduction of risk factors for heart disease compare with treatment of preventable heart disease?
A discerning eye can see that prevention cannot impact all types of heart disease, e.g., already established unexplainable congenital heart defects, or right heart failure due to hereditary chronic lung disease. Many (perhaps most) diseases we find in medical textbooks do not have easily defined causes which can be short-circuited by prevention maneuvers. Just as we cannot prevent a disease in a non-at-risk population (i.e., a population that cannot get the disease in the first place – men don’t get ovarian cancer; women who’ve had total hysterectomies cannot get uterine cancer), we cannot prevent a disease for which we do not know predisposing risk factors or causative agents.
[Let me be clear that this doesn’t mean we can’t prevent disease without knowing its proximate cause. Scurvy was prevented in sailors without knowing about vitamin C per se; it was prevented by an observation of the relationship of the lack of citrus fruits and the profound spread of scurvy among sailors. In this case citrus fruits were a surrogate for the active vitamin C ingredient. There are many other such examples in the history of preventive medicine. See, for example. Burt Gerstman’s Epidemiology Kept Simple, 2003, p 290]
One other problem with the cost-effectiveness analyses typically done: they discount the value of future lives. This almost automatically puts prevention at a disadvantage because by definition the effects of prevention are in the future, while the effects of treatment are usually gained in the short-term. So for every life saved in treatment this year, we would need two or more lives saved in the future through prevention if we discount lives. This has interesting ethical implications, the most obvious of which is: why is a life in the future worth less than a life right now? Menzel explores this issue in detail in chapter 11 of Prevention vs. Treatment and I won’t recount his discussion here other than to say that the economic rationale of discounting monetary value most likely doesn’t hold for the value of life, especially when an ethical analysis is done. Because we make health policy including not just dollars but also values, this may hold a very telling modification of the policy implications of Russell’s analysis.