This negligence action arises out of an automobile accident between plaintiff and defendant. The trial court directed a verdict for defendant on the ground that plaintiff did not produce sufficient evidence that defendant’s negligence caused her injuries. We review to determine whether there is expert testimony from which a rational juror could find that there is a reasonable medical probability that defendant’s negligence caused plaintiff’s injuries.
See Chouinard v. Health Ventures,
At trial, plaintiff adduced the following testimony by her chiropractor regarding causation:
“Q Now, do you have a medical opinion on the causation of [plaintiff’s] neck injury? You testified something about the whiplash. But do you have a specific causation of the condition you treated her for when you first started seeing her on January 27 of 2000?
“A Yeah. It is my opinion that the condition that I treated her for was solely a result of the accident that she had two days prior to coming into my office.”
At the close of plaintiffs case, defendant moved for a directed verdict, arguing that the testimony just quoted was insufficient to establish causation under the reasonable medical probability standard. The trial court agreed and granted the motion. On appeal, plaintiff argues that her expert was not required to utter the particular words “reasonable medical probability’ to establish the element of causation and that his medical opinion that plaintiffs injury was “solely the result” of the accident was sufficient. Defendant agrees that particular words were not necessary but argues that the testimony was insufficient because it did not disclose the reasons for the expert’s opinion. In defendant’s view, “[t]he *18 reasonable medical probability standard does not exist simply to ensure that a medical expert testifies; that standard exists to ensure that the expert’s opinion is based on generally accepted medical science and diagnostic practices.”
We review the grant of a directed verdict for any evidence in the record from which a rational juror could find for the plaintiff on every element of her claim.
Kotera v. Daioh Int'l U.S.A. Corp.,
Oregon cases discussing the sufficiency of expert opinion testimony about a “reasonable medical probability” of causation have primarily focused on (1) whether such expert testimony is required,
see Chouinard,
Instead, defendant contends that the expert’s testimony was insufficient to establish causation because the expert did not explain the scientific principles underlying that opinion. In defendant’s view, no rational juror could find, based solely on the bare opinion of a qualified expert, that the accident at issue here caused plaintiffs injuries. Defendant argues that, without an explanation of
why
the expert believed that the accident caused the injury, the jury could only speculate about whether he arrived at his opinion by applying scientifically valid principles. Defendant asserts that
Hutchison v. Aetna Life Insurance Co.,
In that case — an action to enforce an insurance policy — the issue was whether the death of the plaintiffs husband resulted from an accidental injury covered by the defendant’s policy. The plaintiff contended that the death was the eventual result of an accident that her husband had had at work several months earlier. At the conclusion of a hypothetical question, the plaintiffs attorney asked an expert witness, “Assuming those to be the facts, Doctor, would you say that the accident was the probable cause of his death?” Id. at 645. The witness answered, ‘Well, from a medical and surgical standpoint, it strikes me that this whole thing which was the active cause of this was an accident which the man had.” Id. The Supreme Court concluded, and the plaintiff conceded, that the witness’s testimony was so indefinite and confusing as to be “wholly devoid of probative value.” Id. at 649. As a result, the court did not consider the testimony in determining whether there was sufficient evidence to support a verdict for the plaintiff. Although the court *20 did not elaborate on its reasoning, it appeared to conclude that the challenged testimony — couched in vague terms such as “it strikes me,” “active cause,” and “an accident” — failed to convey a coherent opinion that the accident probably caused the decedent’s death. The court did not, however, adopt a categorical rule that an expert must explain the scientific basis for his or her opinion in order for the opinion to qualify as evidence sufficient to withstand a motion for directed verdict on the issue of causation. Defendant has cited no authority, and we have found none, that imposes such a requirement. We decline to impose one here.
In this case, plaintiffs expert testified about his medical qualifications on direct examination. Plaintiffs counsel asked whether the expert had a “medical” opinion regarding causation, and the expert answered that he did. He then stated his opinion “that the condition that I treated her for was solely a result of the accident that she had two days prior to coming into my office.” From that evidence, a rational juror could infer that the expert had a scientifically valid basis for his opinion and was not simply speculating about causation.
1
The expert’s failure to explain how he arrived at his opinion could result in the jury giving the opinion less weight than it otherwise might, but that omission is not grounds for a directed verdict.
Cf. Chance v. Alexander,
In sum, we conclude that plaintiffs expert’s testimony that plaintiffs injuries were solely the result of the accident was sufficient evidence of causation to create an *21 issue of fact for the jury. It follows that the trial court erred in directing a verdict for defendant.
Reversed and remanded.
Notes
If defendant was concerned that plaintiff was offering an unfounded opinion, she could have requested an OEC 104 hearing for the court to determine whether the expert’s opinion was based on knowledge that is considered scientifically valid under the multifactor analysis described in O’Key. See Laird C. Kirkpatrick, Oregon Evidence § 702.04, Art VII-35 (4th ed 2002) (Scientific validity is a preliminary question for the court to resolve in an OEC 104 hearing.).