Friday, November 27, 2009

The Illusion of Costless Benefits: Mammograms, Pap Tests, and the Inspection of Goat Entrails

Last week the results of two major research studies challenged the utility of two cancer screening tests: mammograms and Pap tests. As a libertarian philosopher, I thought I’d add a few caveats.

Scientific predictions of impending downward spirals are subject to two kinds of costly errors that waste time, effort, and resources: false positives and false negatives. Mammograms and Pap tests are subject to a high incidence of both, which raises two questions. 1.) Under what conditions does it make sense for an individual to undergo these imperfect screening tests? 2.) Under what conditions does it make sense for government to encourage or discourage the use of these imperfect screening tests? The cost/benefit ratios for these tests are enormously complex and include both biological and economic determinents. Recent scientific evidence indicates that for individuals, the utility ratios for both mammograms and Pap tests vary based on one's medical history, family history, and age. If you have had cancer before, or if you have a strong family history of cancer, evidence suggests that you probably ought to be tested.

Once it is determined that you ought get routine mammograms and/or Pap tests, then scientists must then determine at what age routine testing ought to begin and end, and how often you ought to be tested? Surprise! The corporations that manufacture these tests and the specialists that interpret the results prefer that more women get tested more often. Third-part payers prefer fewer women being tested less often. As scientists gather empirical evidence over time, the cost/benefit ratios for various groups change and the status quo becomes subject to revision, and some women who were previously recommended for routine may no longer be routinely tested, and/or some who were not recommended for routine tested may be routinely tested.

Although about 3-4 million Pap tests are performed annually, only about 13, 000 cases of cervical cancer are diagnosed, and 4,000 women die from it every year. In the case of mammograms, 1,900 women must be screened for a decade in order to save a single life. In light of this body of statistical evidence, under what circumstances might government encourage women to undergo these tests, or mandate insurance companies to pay for these tests? Here lies the political problem.

For better or worse, we have all been culturally programmed to ignore the economic dimension of health care: an ideology that is reflected in the often cited moral pronouncement: “Regardless of how much it costs, if we can save one life… it’s worth it.” This high-minded ideology has had, not only a devastating effect cost of health care, it has also undermined scientific medicine. Based on the “save one life principle,” if we screen 100 million persons and save one life, it’s worth it! Or, if we spend $50,000 keeping 95 year old Uncle Joe alive in an intensive care unit for three more months, it’s worth it. And, of course the “save one life principle” becomes even more pernicious when someone else pays for the tests and/or hospital bills.

We Americans are more likely to want and/or undergo any screening test if a third party (private health insurance, Medicare, Medicaid etc.) pays for it. Economists call it “moral hazard.” So how do third-party payers decide which tests to pay for? Well, state and federal governments usually decide for them by force third-party payers to pay for certain tests. How do legislators decide which tests to mandate? We would all like to believe that scientific evidence plays a prominent role, but that’s not how our political system works. What usually happens is that the manufacturers of the tests and the would-be beneficiaries of low-probability, costless benefits get together and form coalitions that vigorously lobby state legislators. How hard is it for male legislators to refuse to cover Pap tests and/or mammograms when confronted by an army of female lobbyists?

Libertarians are critical of any system where government presides over the distribution of "costless benefits." If the goat industry and a group of patients that believe in the prognostic value of the inspection of goat entrails could form an effective lobby, third-party payers could be forced to pay for those tests. The fundamental problem in the United States is that health care policy is often forged on the basis lobbying acumen, often at the expense of science. As the goat industry plans its lobbying campaign to force third-party payers to cover the inspection of goat entrails as an alternative to mammograms and pap tests, we can begin to understand why the quality and cost of health care in the United States will remail suboptimal.

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