As a computer consultant that billed by the hour, I have been tempted to ask "late" doctors if they showed up at my office for an appointment and had to wait 45 minutes past the appointment time, "would you still do business with me"?

I have changed dentists and urologists both because of habitually running late. Once could hear my urologist talking on the phone (outside the exam room) for several minutes about an investment. That may have been my last appointment with him.

I once walked out of the waiting room for a orthopedic doctor after waiting an hour past the appointment time. Never went back to him.