To establish a prima facie case of medical malpractice, the plaintiff is required to prove three elements, including the standard of care at the point of treatment, a breach of the standard of care by the defendant, and that the breach was the proximate cause of the injury claimed. Where both sides have presented expert testimony in support of their respective positions, it is for the jury to decide which expert’s testimony is more credible. Texter v. Middletown Dialysis Center, 22 A.D.3d 831 (2d Dept. 2005). Limiting the discussion to the third element, establishing proximate cause in a medical malpractice action requires plaintiff to present sufficient medical evidence from which a reasonable person might conclude that it was more probable than not that the defendant’s departure was a substantial factor in causing plaintiff’s injury. Generally, expert testimony is necessary to prove both the deviation from accepted standards of medical care and to establish proximate cause. Semel v. Guzman, 84 A.D.3d 1054 (2d Dept. 2011).
Where it is important to prove merit to the claims, usually at trial or on a motion for summary judgment, except as to matters within the ordinary experience and knowledge of laymen, expert medical opinion evidence is required to sustain the claim. Amsler v. Verrilli, 119 A.D.2d 786 (2d Dept. 1986). Causation issues which lie within the competence of a jury to determine without expert support are few, and include such claims as injury to an anesthetized patient outside the operative field, foreign objects left behind at surgery, and a psychiatrist’s beating of a patient which bespeaks improper treatment. Pipers v. Rosenow, 39 A.D.2d 240 (2d Dept. 1972). Early in the handling of the malpractice claim, the defense attorney must give close attention to the unique causation issue flowing from each of the potential departures to be defended. Unless the causation issues are thoroughly evaluated with the assistance of defense experts, counsel will be ill prepared to defend those issues when the time arrives.