I think that some people are better at interpreting studies than others, but unfortunately, the state got into the business of regulating who can allege to be an expert. Of particular concern there isn't necessarily the educational requirements, etc., some of which I can understand in a practice setting (though I'd like the whole system and requirements revamped), but rather the explicit and implied threats of revocation of licensure should the "expert" speak in opposition to state orthodoxy.

If you think your doctor is candid or that the doctor patient privilege has any teeth, boy do I have news for you. The attorney-client privilege (short of the crime-fraud and immediate threat of bodily harm exceptions) and the work-product privilege are really the last bastion of confidence and discretion in practice (though there are other issue here).