Successful Aging: Why do some medical practitioners make assumptions based on age?

Q. I recently called my internist to make an appointment for a routine EKG. The receptionist asked the important initial questions: date of birth, then name. After I gave my date of birth which is 1942, she immediately transferred me to the nurse practitioner (NP). I left a message with her and did not get a call back. I called back the receptionist and asked if I were 35, would she have referred me to the NP. She indicated the referral was for those who had chronic conditions. I said I had none