Cumulative trauma claim rates in California have grown by 50% since 2008 and 40% of such claims are filed after an employee is terminated, according to a report released Wednesday by the Workers Compensation Insurance Rating Bureau of California.

The Oakland, California-based agency studied workers comp claims for workplace injuries that result from repetitive mentally or physically traumatic activities extending over a period and found an overall upward trend in such claims. The study did not describe cumulative trauma, but the International Risk Management Institute describes such workplace injuries as that which “arises from the repetition... (of) job tasks over an extended length of time” and that examples include carpal tunnel syndrome and hearing loss.

The California report revealed that such claims “have also been found to be significantly more complex than other claims and much more likely involving multiple claims filed by the same claimant, multiple body parts alleged, psychiatric or mental stress components alleged, and interpreter services.”

The report, which studies industry sectors and regions in the state, show that recent cumulative trauma claim growth relates to claims in the Los Angeles and San Diego regions, which generate 75% of such claims but only 50% of other types of workers comp claims, according to the report.

Recent cumulative trauma claim growth is spread across industries, although the manufacturing and hospitality sectors have experienced the most significant growth rates, according to the report. 22% of claims in manufacturing and 14% in hospitality are considered cumulative trauma cases, compared with 6% of construction-related claims and 7% of clerical claims, according to the report.

The report also said cumulative trauma claims close “significantly slower than specific injury claims, with over 80% still open after 18 months” and that cumulative trauma claim growth in Southern California is concentrated in lower wage workers.