SAN FRANCISCO—California’s Supreme Court has declined to review a controversial ruling that employers and insurers opposed on grounds that it would diminish the objectivity in rating workers compensation disabilities won in reforms adopted in 2004.

The state high court on Wednesday declined to hear the case of State Compensation Insurance Fund vs. WCAB (Almaraz), which California’s Workers’ Compensation Appeals Board combined with another similar dispute involving the Milpitas Unified School District and claimant Joyce Guzman.

The WCAB ruled on the Almaraz/Guzman cases in 2009, finding that a schedule California adopted after the 2004 reforms for rating permanent disabilities can be rebutted with certain evidence.

The WCAB also said doctors must stay within “the four corners” of the American Medical Assn.'s Guides to the Evaluation of Permanent Impairment when determining an injured worker’s level of disability.

That meant that while doctors had to apply the guides when rating a disability, they could rely on any chapter or table in the reference materials, court records show.

In an appeal of Guzman before California’s 6th District Court of Appeal, employers and insurers argued that the WCAB’s decision allowed impairment ratings to be based on chapters within the guides that did not apply to the employee's injury, court records show.

Stricter application sought

They argued for a stricter application of the guides, arguing that would promote consistency and objectivity in disability ratings as intended by the 2004 reforms.

However, in 2010 the state appellate court upheld the WCAB’s finding in Guzman. It said the AMA guides are not absolute and doctors may apply “clinical judgment” to rate the percentage of disability loss suffered by injured workers because a “mechanical application” of the guides is not appropriate.

A separate appellate court, meanwhile, had declined to review the WCAB’s decision in Almaraz. On Wednesday, the California Supreme Court also declined to review the case.

That means that the appellate court ruling in Guzman now is the law on permanent disability ratings, said a spokesman for the Sacramento. Calif.-based Workers’ Compensation Action Network.

“Now that the Supreme Court has dealt this death blow, we have reached a point where we can definitively say we lost a substantial measure of the objectivity and predictability lawmakers intended when they revised our (permanent disability) system in 2004,” said the spokesman for the employer and insurer coalition.