On November 12, 2009, Mr. Strauss sought preauthorization from his health insurer, Premera Blue Cross, to undergo PBT rather than IMRT, but Premera denied the request on the ground PBT was not "medically necessary" within the meaning of the policy.

Mr. Strauss twice unsuccessfully pursued internal appeals of the decision with Premera, and an external review in July 2010 upheld the denial of coverage.

Meanwhile, Mr. Strauss completed PBT in April 2010.

The Strausses subsequently sued Premera, seeking to recover the cost of PBT, insurance bad faith damages, and treble damages for violation of the Washington Consumer Protection Act ("CPA").

The parties stipulated that PBT was costlier than IMRT and was at least as effective in treating prostate cancer.

Premera moved for summary judgment on the ground that the Strausses could not meet their burden to show that PBT was "medically necessary" under the insurance plan.

The parties agreed that PBT would qualify as "medically necessary" if it resulted in fewer adverse side effects compared to IMRT; Premera argued that the Strausses had failed to raise a genuine issue as to that fact.

Acknowledging the absence of clinical studies directly comparing the two therapies, the Strausses relied on declarations from two board-certified radiation oncologists who opined that PBT likely would lead to fewer side effects because it irradiated a smaller amount of healthy tissue.

Premera responded that these expert opinions did not constitute "credible science" and that, in the absence of "randomized controlled trials," the Strausses' arguments about side effects relied "entirely on conjecture, theory, and inadmissible cross-study comparisons."

The trial court granted Premera's motion. An intermediate appellate court affirmed, ruling that the Strausses had to provide evidence in the form of randomized clinical trials to defeat summary judgment.

The dispute reached the Supreme Court of Washington.

The Premera Policy

The Premera Blue Cross policy covered "medically necessary" treatment, defined as treatment conducted:

[i]n accordance with generally accepted standards of medical practice . . . and not more costly than an alternative [treatment] . . . at least as likely to produce equivalent therapeutic or diagnostic results.

The Washington Supreme Court's Decision

The court reversed, holding that the Strausses had raised a genuine issue of material fact as to PBT's relative superiority, in terms of side effects, to IMRT.

In its decision, the court explained that, generally speaking, expert opinion on an ultimate question of fact was sufficient to establish a triable issue and defeat summary judgment.

It added, however, that "speculation and conclusory statements" would not preclude summary judgment.

The court then ruled that the court of appeals decision requiring randomized clinical trials "was error."

According to the court, requiring expert medical opinion testimony to be based on a specific type of research went "beyond the court's limited role at the summary judgment stage."

The court found no dispute that the Strausses' experts were qualified to testify, only a dispute as to the weight or credibility of their opinion testimony. The credit to be given to any witness' testimony, including expert opinion testimony, was "quintessentially a matter for the trier of fact to determine," the court stated.

The court declared that the trier of fact, not the trial court, must determine whether PBT had a superior side effect profile, making it "medically necessary" within the meaning of the insurance policy.

It concluded that because there was conflicting evidence in the record regarding the "medical necessity" element of the Strausses' coverage claim, the trial court had erred by granting Premera's motion for summary judgment.

The case is Strauss v. Premera Blue Cross, No. 95449-6 (Wash. Oct. 3, 2019). Attorneys involved include: Howard Mark Goodfriend, Smith Goodfriend PS, Victoria Elizabeth Ainsworth, Corr Cronin LLP, Patrick A. Trudell, Kornfeld Trudell Bowen & Lingenbrink PLL, for Petitioners. Gwendolyn C. Payton, Kilpatrick Townsend & Stockton LLP, John R. Neeleman, Kilpatrick Townsend & Stockton LLP, Adam H. Charnes, Kilpatrick Townsend & Stockton LLP, for Respondent. Valerie Davis Mcomie, Attorney at Law, Daniel Edward Huntington, Richter-Wimberley PS, as Amicus Curiae on behalf of Washington State Association for Justice Foundation.