Guidelines for physician training in advanced cardiac procedures: the importance of case mix.

In recent years, guidelines have been issued for the standardization of physician training in various advanced cardiac procedures. One area that is often neglected by guidelines committees is the need for an adequate case mix during physician training. Case mix refers to the variety of patients and diseases that the trainee is exposed to during the course of learning a new procedure. Although physicians may perform the requisite number of procedures during their training, if the case mix is inadequate, the physician's competence in performing the procedure and interpreting its results may be inadequate as well.