Medical researchers and politicians are tiptoeing into an area of healthcare that makes some Americans uncomfortable, even angry: pressing doctors and patients to use particular drugs and treatments in order to save money. On the surface, it seems simple enough: Billions of dollars could be saved if everyone adopted the regimens that research showed were best and most cost-effective. The problem is that any push for doctors and patients to make a particular choice collides with the American belief that medical decisions are nobody's business but the patient's and the doctor's.