If the doctor is late or cancels the appointment is there a corresponding fine for the doctor? I personally have never missed an appointment but I've shown up on time for my appointments and sat around for 30 minutes and then got up and left because it was a non-critical visit. The office freaks out telling me I should wait for my appointment and I told him they should be ready at the appointed time otherwise what's the point of the appointment.
Clearly offices get backed up and unexpected things happen but they can call non-critical visits and ask if they want to reschedule or alert me that they are running late. I figure by me leaving it allows them to get their schedule back on track.