Sixth Circuit Issues Opinion of Expert Testimony

The Court of Appeals for the Sixth Circuit has issued an opinion upholding the admissibility of an medical doctor’s opinion on causation based on application of traditional differential diagnosis theory.

In  Best v. Lowe’s Home Centers, Inc., (No. 08-5924) , _ F.3d _ (6th Cir. April 16, 2009)  the court reversed a trial judges opinion to exclude a doctor’s conclusion that the plaintiff’s loss of smell was caused by a chemical spill at defendant’s store.

The court said

“A medical-causation opinion in the form of a doctor’s differential diagnosis is reliable and admissible where the doctor (1) objectively ascertains, to the extent possible, the nature of the patient’s injury, see [In re Paoli Railroad Yard PCB Litigation, 35 F.3d] at 762 (“A physician who evaluates a patient in preparation for litigation should seek more than a patient’s self-report of symptoms or illness and . . . should . . . determine that a patient is ill and what illness the patient has contracted.”), (2) ‘rules in’ one or more causes of the injury using a valid methodology, and (3) engages in ‘standard diagnostic techniques by which doctors normally rule out alternative causes’ to reach a conclusion as to which cause is most likely. Id. at 760. In connection with the third “rules out” prong, if the doctor “engage[s] in very few standard diagnostic techniques by which doctors normally rule out alternative causes,” the doctor must offer a “good explanation as to why his or her conclusion remain[s] reliable.” Id. Similarly, the doctor must provide a reasonable explanation as to why “he or she has concluded that [any alternative cause suggested by the defense] was not the sole cause.” Id. at 758 n.27.”

The court also noted that

“Lowe’s has pointed to several potential problems with Dr. Moreno’s expert opinion. But our function is not to determine whether the opinion is airtight and conclusively proves the cause of Best’s anosmia. Rather, the court’s role as gatekeeper is to decide whether Dr. Moreno performed his duties as a diagnosing physician to the professional level expected in his field. See Kumho Tire Co. v. Carmichael, 526 U.S. 137, 152 (1999). In light of this standard, we conclude that Dr. Moreno’s differential diagnosis testimony meets the threshold level of admissibility under Daubert.”

As the court explained,

“[a]n ‘overwhelming majority of the courts of appeals’ agree, and have held ‘that a medical opinion on causation based upon a reliable differential diagnosis is sufficiently valid to satisfy the first prong [reliability] of the Rule 702 inquiry.’” Best, _ F.3d at _ (quoting Westberry v. Gislaved Gummi AB, 178 F.3d 257, 263 (4th Cir. 1999) (collecting cases from the First, Second, Third, Ninth, and D.C. Circuits)).

Read a more complete summary of the opinion at Federal Evidence Review, an excellent site that I rely on to keep current with major developments in the law of evidence in the federal courts.

For a copy of the opinion click here.