Controversial medical testimony is admissible, Oregon Court of Appeals holds

Oregon courts should not exclude scientific expert testimony simply because it is controversial or arguably invalid, according to an opinion issued this week by the Court of Appeals.  In Kennedy v. Eden Advanced Pest Technologies, plaintiff claimed he suffered from multiple chemical sensitivity, and that defendant's application of pesticides in his home aggravated the condition and caused injury.  At trial, the court excluded testimony from his treating physician regarding the diagnosis, his opinion of causation, and proposed treatment.  To support admissibility, plaintiff offered evidence that multiple chemical sensitivity is recognized as a diagnosable condition by a number of medical groups.  Defendant responded with testimony from another doctor who said the condition has never been subject to scientific proof and is not recognized within mainstream medical practice.

On appeal, plaintiff argued that the testimony should have been admitted as scientific evidence.  Judge Edmonds, writing for the Court, agreed, stating that controversy within the scientific community is not necessarily a basis to exclude scientific evidence.  Plaintiff had shown that the testimony was relevant, would have assisted the jury, and was unlikely to have caused confusion or have misled the jury.  He concluded, "given the Oregon legislature's strong policy to aid the trier of fact to understand the evidence presented at trial in the context of the parties' theory of the case, we believe that the legislature intended controversial evidence like [the treating physician's] testimony to be presented to the jury."