Jennings Decision Will Impact Admissibility of Expert Testimony in California

January 26, 2004
Thelen Reid Report No. 90

Thelen Reid's appellate team, led by partner Curt Cole in our Los Angeles office, recently argued a case with potentially groundbreaking significance regarding the admissibility of expert testimony in California. The California Court of Appeal, Fourth Appellate District, Division One, has certified for publication Jennings v. Palomar Pomerado Health Systems, Inc., et al. (891894-191) -- an appeal tracked closely by several law firms, many of whom represent clients in toxic tort and asbestos litigation. Given the complicated facts and controversial outcome of the case, the court's decision to publish its decision was clearly the result of several requests for it to do so.

The Court of Appeal's decision in Jennings is groundbreaking because it allows a judge to consider and reject, if necessary, the basis of an expert's medical opinion. Although the opinion does not go as far as the federal decision in Daubert v. Merrill Dow Pharmaceuticals, Inc. 509 U.S. 579 (1993), which has given federal court judges a more definitive "gatekeeping" function, the decision does require that the basis for an opinion be sound, and not speculative, before reaching a jury. The Court relied on Evidence Code section 801, requiring that expert testimony be admitted only if it assists the trier of fact, as a basis for its opinion. The court reasoned:

[A]n expert's opinion that something could be true if certain assumed facts are true, without any foundation for concluding those assumed facts exist in the case before the jury, does not provide assistance to the jury because the jury is charged with determining what occurred in the case before it, not hypothetical possibilities... Similarly, an expert's conclusory opinion that something did occur, when unaccompanied by a reasoned explanation illuminating how the expert employed his or her superior knowledge and training to connect the facts with the ultimate conclusion, does not assist the jury. In his latter circumstance, the jury remains unenlightened in how or why the facts could support the conclusion urged by the expert, and therefore the jury remains unequipped with the told to decide whether it is more probable than not that the facts do support the conclusion urged by the expert. An expert who gives only a conclusory opinion does not assist the jury to determine what occurred, but instead supplants the jury by declaring what occurred.

The Jennings opinion also confirms the burden that a plaintiff must satisfy to prove medical causation. The opinion states:

Thus, proffering an expert opinion that there is some theoretical possibility the negligent act could have been a cause-in-fact of a particular injury is insufficient to establish causationÂ…. Instead, the plaintiff must offer an expert opinion that contains a reasoned explanation illuminating why the facts have convinced the expert, and therefore should convince the jury, that it is more probable than not the negligent act was a cause-in-fact of the plaintiff's injury.

The Court of Appeal has denied a Petition for Rehearing. However, a Petition for Review has been filed with the California Supreme Court. The time is ripe for the Court to consider this issue because several recent cases, such as Roberti v. Andy's Termite & Pest Control, Inc. (2003) 113 Cal.App.4th 893, could be considered as conflicting with Jennings.

In Roberti, the California Court of Appeal, Second Appellate District, held that the federal admissibility standards established under Daubert were not applicable to an expert's medical causation opinion. To the extent that parties may attempt to rely on the Roberti decision to argue that it precludes California trial courts from reviewing the admissibility of expert medical causation testimony prior to trial, the Roberti decision could be interpreted as conflicting with Jennings.

If Jennings and other related cases are upheld in favor of allowing the court to perform a gatekeeping function, even if minimal, this decision could be helpful not only in medical malpractice cases, but in other related cases, such as toxic torts, products liability and asbestos defense, because it requires that experts have a sound basis for their opinions before they reach the jury.

For any questions concerning the California Court of Appeal's decision in Jennings, or to discuss its impact on future cases, please contact the authors of this report: