Why would a certification be reason to feel compelled to answer unconstitutional questions? If the People are willing to cede their rights and freedoms because someone has a "certification", you can bet that there will be sufficient "certifications to ensure all our rights are wrested away.
I think lack of a certification would give a patient more comfort in not answering such a question.
I am a doctor, and I do not discuss firearms with my patients unless we are discussing the merits of a particular firearm.
However, the leftist doctors will sign on to this unconstitutional questioning, and patients WILL feel intimidated.