Joseph: I don’t think it’s always so black and white. And a lot of it is related to a doctor’s experience. The same type of infection that’s viral 90% of the the time is bacterial in 10% of cases. And not always does the doctor know for sure which one it is. (When a specific cancer treatment, to make an extreme comparison, is only successful 10% of the time, even the best of doctors will latch onto it in the absence of a better alternative, I believe.)
So if a patient knows that last time his sinus infection, for example, was cleared with anti-biotics, why wouldn’t he want the same treatment for his new infection? And if the doctor isn’t 100% certain that the patient is wrong, why wouldn’t he cave and prescribe it?