I was roomed and ready for my appointment about 10 minutes early.  She did not come into the room for 15 minutes after my scheduled time so the lights had gone out.  When she came in was surprised it was dark and said "sorry";  however, no apology for being 15 minutes late.  I get that providers can be delayed by other patients but a simple "sorry I am late" goes a long way.  
CT ABMC