(a) The applicable standard of care and a defendant's failure to meet the standard of care, if at issue, shall be established in medical professional liability cases by the plaintiff by testimony of one or more knowledgeable, competent expert witnesses if required by the court. A proposed expert witness may only be found competent to testify if the foundation for his or her testimony is first laid establishing that: (1) The opinion is actually held by the expert witness; (2) the opinion can be testified to with reasonable medical probability; (3) the expert witness possesses professional knowledge and expertise coupled with knowledge of the applicable standard of care to which his or her expert opinion testimony is addressed; (4) the expert witness's opinion is grounded on scientifically valid peer-reviewed studies if available; (5) the expert witness maintains a current license to practice medicine with the appropriate licensing authority of any state of the United States: Provided, That the expert witness's license has not been revoked or suspended in the past year in any state; and (6) the expert witness is engaged or qualified in a medical field in which the practitioner has experience and/or training in diagnosing or treating injuries or conditions similar to those of the patient. If the witness meets all of these qualifications and devoted, at the time of the medical injury, sixty percent of his or her professional time annually to the active clinical practice in his or her medical field or specialty, or to teaching in his or her medical field or speciality in an accredited university, there shall be a rebuttable presumption that the witness is qualified as an expert. The parties shall have the opportunity to impeach any witness's qualifications as an expert. Financial records of an expert witness are not discoverable or relevant to prove the amount of time the expert witness spends in active practice or teaching in his or her medical field unless good cause can be shown to the court.
(b) Nothing contained in this section limits a trial court's discretion to determine the competency or lack of competency of a witness on a ground not specifically enumerated in this section.