SAN JOSE, Calif.—American Medical Assn. Guides are not absolute and doctors may apply “clinical judgment” to rate the percentage of permanent disability loss suffered by injured workers, a California appellate court has ruled.

Several employer and insurance entities filed amicus briefs in Milpitas Unified School District vs. Workers’ Compensation Appeals Board and Joyce Guzman, which became known as the Guzman case.

The briefs supported the school district’s attempt to overturn a 2009 California Workers' Compensation Appeals Board decision, which essentially stated that there is room for other medical opinions when determining the rate of impairment suffered by an injured worker.

The school district argued that the fifth edition of the AMA’s Guides to the Evaluation of Permanent Impairment as written is not rebuttable and should be the final word on rating injuries, court records show.

Otherwise, the consistency and objectivity in rating injuries that employers sought in reforms adopted by California in 2004 are lost, argued opponents of the Workers’ Compensation Appeals Board’s decision.

But the 6th Appellate District of California’s Court of Appeal in San Jose upheld the appeals board’s broader view, ruling Thursday that the state’s labor code “recognizes the variety and unpredictability of medical situations” and not a “mechanical application” of the Guides.