I agree. the best security is to email a clear list of queries before each visit.
If you don't have print proof then ask for the nurse's/receptionist name and also ask them to repeat what you are requesting or advising. At teh end of each such contact I suggest you say "I would like to confirm the main points of this call..."

@contentandwell, You make such good points! I always wonder what the nurse I speak with by phone relays to the doc but for present, this is my best access for questions outside office visits.

@contentandwell @sru97 and others in this conversation. I agree that using the patient portal is one of the better ways of communicating with your physician between appointments. From a practical point of view, you don't have to wait on hold and give a message (with many repeats) to a receptionist (who may not have a medical background and therefore may not understand your question) which ends up resulting in a long telephone call and leaves you unsure that your correct message gets to your doctor. I basically have chosen two health care facilities in my area to use for all of my medical care. Both of these use EPIC as their patient portal. It makes communication regarding test results and appointments very easy.