Evidence—Necessary Qualifications of Causation Expert in Medical Malpractice Cases

Rasor v. Northwest Hospital LLC, 789 Ariz. Adv. Rep. 4 (App. Div. II, April 24, 2018) (J. Espinosa)

QUALIFICATIONS REQUIRED OF CAUSATION EXPERT IN MEDICAL NEGLIGENCE CASE ARE LESS THAN REQUIRED OF STANDARD OF CARE EXPERT/BASICS OF RULE 702 ARIZ. R. EVID. APPLY/NURSE MAY QUALIFY

Plaintiffs sued Northwest Hospital for allowing a bed sore to develop post heart surgery and then failing to properly treat and care for the wound.  Plaintiff offered a board certified wound care registered nurse to testify as to a breach of the standard of care and causation.

The defendant hospital was granted summary judgment based upon a finding the plaintiffs' expert was not qualified to provide standard of care testimony. The Arizona Court of Appeals and Arizona Supreme Court affirmed, but further found that the plaintiff should be given additional time  to find a qualified standard of care expert.  The supreme court remanded to the court of appeals for a determination as to whether or not causation opinions were required in the case and if so whether the plaintiffs' current nursing expert, while unqualified to render standard of care decisions, could nonetheless render causation opinions.  The court of appeals responded affirmatively to both questions and reversed and remanded to the trial court, requiring plaintiff be given leave to file a motion to obtain additional evidence pursuant to Rule 56(d), Ariz. R. Civ. P.

While plaintiffs established that failure to relieve pressure on a patient's tailbone will ultimately cause a decubitus ulcer, the defendant's expert identified a number of additional contributory factors to the creation of such an ulcer based upon this specific plaintiff's medical history.  Where alternative causes of injury in a medical negligence case are presented, plaintiffs must establish causation by qualified expert opinion.

 Rule 702 Ariz. R. Evid. and A.R.S. § 122603(H)(2) similarly define and “expert” as “a person who is qualified by knowledge, skill, experience, training or education to express an opinion regarding a licensed health care professional's standard of care or liability for the claim." While A.R.S. §122604(A) sets forth additional qualifying criteria which must be met by plaintiffs' standard of care expert, there is no such additional qualifying criteria for a medical malpractice causation expert.

 It is important to note that here the Arizona Court of Appeals expressly rejected the defendant's request that a “bright line” rule be announced that a nurse can never establish causation in a medical negligence case. Rather the court found that in appropriate circumstances, such as exist here, a nurse may establish causation.  "The test of whether a person is an expert is whether a jury can receive help on a particular subject from the witness. The degree of qualification goes to the weight given the testimony, not its admissibility."

 Here plaintiffs' nurse expert had extensive training and experience in wound and bed sore etiology and care. Defendant's attacks on her qualifications and the basis of her opinions can be developed in cross examination and through the defendant's own experts, and properly goes to the weight of the nurse's testimony and not its admissibility.