In accordance with the scenario where the doctor’s office (as opposed to to doctor) called. The questionable scenario we might be talking about is one where the doctor’s office is doing ‘outcomes research’.
That is to say, perhaps the patient has been given a scrip for drug X, and the nurse, who works part time for the doctor and an HMO customer who pays her on the side, is interested in finding patients who take drug X that are ALSO taking drug Y, he/she might illegally call the pharmacy the patient regularly goes to and ask about whether drug Y is being taken by the patient, she could then tell the HMO who could recruit them for a study, clinical trial, etc.
Maybe it’s not a big deal since it ultimately might be used to help the patient, but imagine the problems if you, say, were HIV-positive, and some telemarketer for the HMO calls your house and the family member who doesn’t know about it suddenly finds out when their asked if the patient is home, and if not, could they please call the HMO who is interested in interviewing them to find out how much their life sucks dealing with HIV, or other such scenario.
I’ve heard of these problems happening before because nurses want to make money on the side, and are sometimes asked (and are even encouraged by the doctors) to help out in research. In this case, however, they are supposed to ask the patient taking drug X (usually by mail) IF they are taking drug Y, and if so, would they be interested in participating in a study. A greedy nurse might be a little less scrupulous, especially if he/she is paid on per patient recruited basis