You can try to inform them and getting a signature on a form might help when the inevitable backlash happens, but the patients usually have the entitlement attitude and nothing changes that.
It's one thing if the doctor (or his staff) clearly informs the patient that a test or a procedure isn't a standard part of what they came in for and won't be covered by insurance. It's another story if the doctor doesn't inform the patient, but just goes ahead with the test or procedure.
A number of years ago, the chiropractor I had seen for years was killed in a car accident. I started going to a different chiropractor, who was recommended to me by a friend. My old guy always did the same treatment, no matter what ache I went in for, and it always worked. The new one was always attending seminars to "stay on top of the state of the art." My problem was always lower back -- I was injured in a car accident when I was 14 and the lower back took the hit. One day this new chiropractor blithely informed me that he had been to a workshop on TMJ (tempro mandibular joint -- "jaw") problems. Lo and behold, even though I was there for lower back pain, he suddenly began "adjusting" my jaw. The jaw "adjustment" took all of about 15 seconds, and he added $15 to the bill for the TMJ procedure. Clearly, he was just paying for the seminar by tacking on a useless procedure for all his patients.
I stopped seeing that chiropractor.
I also once walked out of a surgical out-patient clinic because a doctor played fast and loose with disclosure and informed consent. I was scheduled for an elective procedure that was described to me as to be done under a "local." When I arrived at the clinic, the first person who came in to see me was an anesthesiologist. I asked why I needed an anesthesiologist for a procedure that was to be done under a local. He said, "Well, it's really a local with sedation. We knock you out, but it's not like full anesthesia." Then the surgeon came in and told me the same thing. I balked, partially because I just didn't want to be fully knocked out, and partially because I had driven myself to the clinic and if I was knocked out I wouldn't be allowed to drive myself home.
The doctor copped an attitude and gave me an ultimatum: find someone to drive me home, or don't do the procedure. That made things very simple: I got dressed and walked out. I later found a different doctor who really did the procedure under a local, who couldn't understand why anyone
wouldn't do it that way. I drove myself to the appointment, and I drove myself home.
Doctors who fail to inform patients about matters pertaining to the patient's care are not acting ethically. The problem is that too many doctors think they are gods and that they're too important to waste their valuable time explaining to a patient what's about to happen.