Oregon Court of Appeals Gives Clarity to Complicated Pre-Existing Condition Cases
In an opinion issued on April 2, 2025, the Oregon Court of Appeals clarified the causation standard that applies when a new/omitted medical condition claim involves a standalone pre-existing condition that is exacerbated by a work injury. In Barnes v. Cache Electric, 339 Or App 371 (2025), the Court of Appeals held that a pre-existing condition that is exacerbated by a work injury can be compensable, but only if the work injury is the major contributing cause (greater than 50 percent) of a pathological worsening of the pre-existing condition. Id. at 374.
To understand the impact of Barnes, it is important to understand the foundational law surrounding new/omitted medical condition claims. The starting point for a new/omitted medical condition claim is that the claimant must prove the claimed condition exists and that the work event was a material contributing cause of the disability or need for treatment of the claimed condition. Maureen Y. Graves, 57 Van Natta 2380, 2381 (2005). Material contributing cause has been described as a substantial cause, but not necessarily the sole cause or even the most significant cause. Titus Dewitt, 71 Van Natta 19, 21 (2019). In reality, material contributing cause is a relatively easy standard for a claimant to meet.
When an otherwise compensable injury combines with a statutory preexisting condition (forming a combined condition), the carrier has the burden of establishing that the otherwise compensable injury is not the major contributing cause of claimant’s disability/need for treatment of the combined condition. ORS 656.005(7)(a)(B). However, a combined condition requires two distinct conditions, and a symptom of a pre-existing condition and the pre-existing condition itself cannot give rise to a combined condition. Carrillo v. SAIF, 310 OR App 8, 13 (2021). As a result of Carrillo, the employer cannot avail itself of the combined condition defense when the new/omitted medical condition claim is based on a work injury causing a pre-existing condition to become symptomatic.
Prior to Barnes, a line of cases suggested the material contributing cause standard applied when a new/omitted medical condition claim involved an injury that exacerbated a pre-existing condition or caused it to become symptomatic. Applying the material contributing cause standard to such new/omitted medical condition claims is problematic for employers and insurers. A work injury that renders a preexisting condition symptomatic may be considered a material contributing cause of a claimant’s disability/need for treatment for that condition. Jason Griffin, 64 Van Natta 1954, 1955 (2012). See also Edward K. Merriweather, 65 Van Natta 2219, 2220 (2013) (a work injury that renders a preexisting condition symptomatic may be considered a material contributing cause of a claimant’s disability/need for treatment for that condition).
In Walid Almohammad, 75 Van Natta 434 (2023), the Administrative Law Judge evaluated the compensability of claimant’s new/omitted medical condition claim for right foot conditions as an occupational disease and upheld the employer’s denial. While the Workers’ Compensation Board affirmed the denial, it also assessed whether the new/omitted medical conditions would be compensable if analyzed as an injury. The Workers’ Compensation Board stated, “we acknowledge that a compensable injury can be established when a work event aggravates symptoms associated with a claimant’s preexisting condition. Yet, the record must still establish that the work event was a material contributing cause of claimant’s disability or need for treatment.” Id. at 436.
More recently, the Workers’ Compensation Board issued Catherine Booth, 77 Van Natta 21 (2025). At the hearing level, the Administrative Law Judge assessed the compensability of right wrist osteoarthritis as an injury, rather than an occupational disease. As a reminder, arthritis is statutorily defined as a pre-existing condition under Oregon Workers’ Compensation law. The Administrative Law Judge, citing Carrillo and Almohammad, applied the material contributing cause standard to what the Administrative Law Judge described as a “symptomatic flare-up of previously asymptomatic right wrist arthritis.” Because the Administrative Law Judge considered the work injury to be a material contributing cause of a need for treatment of a symptomatic flare of pre-existing right wrist osteoarthritis, the employer’s denial was set aside. The Workers’ Compensation Board ultimately reversed the Administrative Law Judge on the basis that the claim should have been analyzed as an occupational disease (and subject to the major contributing cause standard), but it did not address whether the new/omitted medical condition claim, if analyzed as an injury, was subject to a material contributing cause standard. Booth highlights how the material contributing cause standard has been applied to new/omitted medical condition claims involving an injury that exacerbates a pre-existing condition.
This brings us to Barnes. The condition at issue was the claimant’s pre-existing cervical arthritic condition identified as cervical spondylosis. Claimant’s attorney argued the cervical sprain/strain injury made claimant’s pre-existing spondylosis symptomatic and require treatment, and this finding required the conclusion that the new/omitted medical condition claim for pre-existing spondylosis was compensable as a standalone condition, independent of a combined condition.
The Court of Appeals disagreed. In a departure from applying the material contributing cause standard, the Court of Appeals clarified that a pre-existing condition that is exacerbated by a work injury can be compensable, but only if the work injury is the major contributing cause of a pathological worsening of the pre-existing condition. Because the evidence did not support that the work injury was the major contributing cause of the worsening of pre-existing cervical spondylosis, it was not compensable as a standalone condition, separate from the pre-existing component of a combined condition.
While Barnes is a welcome decision for employers and insurers, assessing compensability with a pre-existing condition is still complex, and often requires the assistance of a workers’ compensation attorney. If you have any questions about whether a pre-existing condition is compensable, you can contact me at eberglund@sbhlegal.com or at (503) 776-5431.
Posted by Eric Berglund.
