Medical expert testimony concerning the causation of a medical condition will be considered pure opinion testimony--and thus not subject to Frye analysis--when it is based solely on the expert's training and experience. And there is always the possibility that two experts may reach dissimilar opinions based on their individual experience. However, a disagreement among experts does not transform an ordinary opinion on medical causation into a new or novel principle subject to Frye.
After sustaining injuries in four separate car accidents between August 1995 and January 1998, Marsh (plaintiff) filed a negligence suit against Robert Valyou, Avis Rent-A-Car (Avis), and others involved in the car accidents (defendants). She claimed the accidents caused her to suffer fibromyalgia.
Avis moved to preclude Marsh from presenting expert testimony that the accidents caused her fibromyalgia, arguing that the testimony did not meet the Frye standard for admissibility because the premise that trauma can cause fibromyalgia had not been generally accepted in the scientific community. The trial court held a Frye hearing and, after reviewing numerous documents related to fibromyalgia and hearing arguments of counsel, granted the motion. It later became apparent that Marsh intended to introduce evidence that the accidents caused "myofascial pain syndrome" (MPS). Again, Avis challenged the testimony under Frye and the trial court precluded evidence of a causal link between trauma and MPS. Marsh then announced she had no claims apart from fibromyalgia and MPS, and the trial court entered summary judgment. Marsh appealed.
Should the expert testimony have been allowed?
The Court held that the trial court err in not allowing Marsh’s experts to testify to a causal link between trauma (the car accidents) and her fibromyalgia, finding that such an opinion would violate Frye. The expert testimony at issue was not "new or novel," and therefore was not subject to Frye. The experts based their opinions about the cause of petitioner's fibromyalgia on a review of her medical history, clinical physical examinations, their own experience, published research, and differential diagnosis. As testimony causally linking trauma to fibromyalgia was based on the experts' experience and training, it was "pure opinion" admissible without having to satisfy Frye. Even if subject to Frye, testimony linking trauma to fibromyalgia satisfied Frye. Numerous published articles and studies recognized an association between trauma and fibromyalgia. A lack of studies conclusively demonstrating a causal link between trauma and fibromyalgia and calls for further research did not preclude admission of the testimony. While the precise etiology of fibromyalgia might not be fully understood, petitioner sufficiently demonstrated the reliability of her experts' testimony.