[koenigdavidmj]

They note that you are behaving outside medical advice, and mention that your insurance might as a result refuse to pay for the procedure.

Whether this is actually the case is a different matter, but that veiled threat should be enough for most.

[fr11]

This is a common meme, that your insurance might not pay for a procedure if you do something against medical advice. I've had a number of doctors claim it. It's false, thankfully.

http://www.uchospitals.edu/news/2012/20120203-billing.html