Liberty Northwest Ins. Corp. v. Spurgeon , 109 Or. App. 566 ( 1991 )

WARREN, P. J.

Employer seeks review of a Workers’ Compensation Board order that held that claimant’s carpal tunnel syndrome is compensable as an occupational disease. We reverse.

Employer does not challenge the Board’s findings, which it adopted from the referee’s order. Claimant worked in employer’s food service for eight years. Her job required significant repetitive motions with both hands. Claimant’s off-the-job activities included crocheting and bowling. The Board found that “idiopathic”¹ factors, such as claimant’s age, gender and borderline diabetes, were either a predisposition to or the major cause of her carpal tunnel syndrome. It also found that her work activities materially contributed to the condition, and that, as between activities off the job and on the job, work activities contributed more.

The Board concluded that the claim was compensable. It held that claimant’s predisposition or idiopathic causes should not be considered and compared only her activities on and off the job to decide which of those activities were the major cause of the onset of her condition. Employer asserts that, in determining the major contributing cause, all factors that contributed to cause the disease must be considered, including idiopathic causes.

At the time relevant to this claim, an occupational disease was defined as

“[a]ny disease or infection which arises out of and in the scope of the employment, and to which an employe is not ordinarily subjected or exposed other than during a period of regular actual employment therein.” ORS 656.802(1)(a).

A disease is compensable if work activities are the major contributing cause of the disease or an aggravation or exacerbation of it. Dethlefs v. Hyster Co., 295 Or 298, 310, 667 P2d 487 (1983); SAIF v. Gygi, 55 Or App 570, 573, 639 P2d 655, rev den 292 Or 825 (1982).

The Board concluded that causes of a disease that are personal to a claimant and independent of anything that happens off the job or on the job should not be considered in deciding whether work is the major contributing cause of the claimant’s disease, relying in part on the principle that an employer takes the employee as it finds her. That analysis fails to take into consideration the difference between a susceptibility or predisposition to a disease and a disease that is actually caused by idiopathic factors, independently of a claimant’s activities or exposures anywhere. An employer is responsible for a disease that a claimant who has a particular susceptibility or predisposition develops due in major part to conditions at work. The predisposition to disease is not a bar to compensability, if work causes the disease. In that sense, the employer takes the employee as it finds her. If, in contrast, a claimant develops a disease in major part because of factors personal to her that are independent of any activities or exposures either off or on the job, the claim is not compensable, even if work contributed to some degree to causing the disease. All causes of a disease, as opposed merely to a susceptibility or predisposition, must be considered in determining which, if any, was the major contributing cause.

Dethlefs v. Hyster Co., supra, and SAIF v. Gygi, supra, do not compel or suggest a contrary result. In both of those cases, the claimants had a disease that was caused both by exposures on the job and off the job. The question was which of those exposures was the major contributing cause of the disease. Neither case involved either a predisposition or idiopathic causes that combined with work-related activities or exposures to cause the disease.

The Board’s order, adopted from the referee, says, in part:

“This case turns on what causative agents are being compared in applying the major cause test. If one is comparing on the job factors with all other causative factors, then the claim is not compensable. If one is comparing only on the job factors with off the job factors without considering claimant’s predisposition, then the claim is compensable.

“The clear weight of the medical evidence is that claimant’s work is a material cause of her carpal tunnel syndrome. The clear weight of the evidence is also that the work exposure is a greater cause than any of claimant’s off the job activities. Finally, the clear weight of the evidence is that claimant’s idiopathic factors including her age, gender and borderline diabetes are a greater factor than either her on the job or off the job activities.” (Emphasis supplied.)

The Board did not distinguish between a predisposition and idiopathic causes. We cannot tell whether it found that the idiopathic factors were causes of claimant’s carpal tunnel syndrome or whether they merely existed as conditions that made her susceptible to carpal tunnel syndrome. Accordingly, we remand to the Board to make that determination and to enter an appropriate order in the light of this decision.

Reversed and remanded for reconsideration.

1 The Board made it clear that, by “idiopathic,” it meant “peculiar to the individual,” rather than “unexplained.”