From Charles Krauthammer:
Think of it this way. Assume that a screening test for disease X costs $500 and finding it early averts $10,000 of costly treatment at a later stage. Are you saving money? Well, if one in 10 of those who are screened tests positive, society is saving $5,000. But if only one in 100 would get that disease, society is shelling out $40,000 more than it would without the preventive care.
That's a hypothetical case. What's the real-life actuality? In Obamaworld, as explained by the president in his Tuesday town hall, if we pour money into primary care for diabetics instead of giving surgeons "$30,000, $40,000, $50,000" for a later amputation -- a whopper that misrepresents the surgeon's fee by a factor of at least 30 -- "that will save us money." Back on Earth, a rigorous study in the journal Circulation found that for cardiovascular diseases and diabetes, "if all the recommended prevention activities were applied with 100 percent success," the prevention would cost almost 10 times as much as the savings, increasing the country's total medical bill by 162 percent. That's because prevention applied to large populations is very expensive, as shown by another report Elmendorf cites, a definitive review in the New England Journal of Medicine of hundreds of studies that found that more than 80 percent of preventive measures added to medical costs.
This doesn't mean we shouldn't be preventing illness. Of course we should. But in medicine, as in life, there is no free lunch. The idea that prevention is somehow intrinsically economically different from treatment -- that treatment increases costs and prevention lowers them -- is simply nonsense.