My hubby has a scheduled appt for an operation on an upcoming monday for 0745 hours. His boss advised him to get a letter from the doctor advising what days he will need for sick leave. Hubby had this letter faxed to him at work indicating the day before surgery and then 2 weeks after that hubby would need sick leave. Boss called the surgeon, without hubby's approval, and spoke about hubby working the night prior to his surgery. Boss sent hubby an email advising that he spoke with the surgeon and there is no reason as to why he cannot work the night prior, therefore, scheduling him to work 5 hours the night prior.

First off, I believe that there is a problem with doctor/patient confidentiality and that problem will be dealt with. My question is: Was my hubby's boss out of line in calling the doctor after the letter of time off was faxed by the doctor?

There is no law that prohibits an employer from asking for clarification of information from the doctor's office. The question seems to have been whether it was medically necessary for you husband to be off work the day before the surgery. Apparently, it wasn't. Whether the doctor's office breached confidentiality is a separate matter.