here's a snippet of an interesting Op-Ed in this morning's NYT:

There is little doubt that the so-called tiered formularies, in which co-payments rise along with the cost of the drugs, are a sensible approach for encouraging consumers to use the cheapest drug suitable for their condition. But the system seems to break down when it moves to Tier 4 drugs where co-payments can be huge and suitable alternatives don’t exist.

The insurers say that forcing patients to pay more for unusually high-priced drugs allows them to keep down the premiums charged to everyone else. That turns the ordinary notion of insurance on its head. Instead of spreading the risks and costs across a wide pool of people to protect a smaller number of very sick patients from financial ruin, insurers are gouging the sickest patients to keep premiums down for healthier people.

http://www.nytimes.com/2008/04/15/op...html?th&emc=th