Report Looks at Cumulative Trauma and Litigated Claims in California Workers’ Comp

March 18, 2024

A California Workers’ Compensation Institute study shows nearly half of all litigated claims in the Los Angeles Basin are cumulative trauma claims that involve physical or mental injuries from repetitive stress, motion, or exposures, rather than from a specific event or accident.

The CWCI study, based on a sample of 1.4 million California work injury claims with 2010 to 2022 carrier notice dates, examines the growth of CT claims as a share of litigated claims in the California workers’ comp system and explores the claim characteristics most associated with CT claims.

The study found that statewide, CT claims rose from 29.4% to 37.5% of all litigated claims over the 13-year study period. Regional results showed that over that same period, CT claims’ share of all litigated claims was fairly stable in Northern California and the Central Valley, but increased in 2022, while in Southern California CT claims’ share of the litigated claims increased steadily throughout the period.

The sharpest increase was in the Inland Empire/Orange County, where CT claims jumped from 30.2% of the litigated claims in 2010 to 40.6% in 2022, slightly more than the increase in Los Angeles County, where CT claims went from 38.6% to 48.7% of the litigated claims, and San Diego where CT claims increased from 25.0% of the litigated claims to 33.4%.

An analysis showed that the differences between the regions were only partially explained by differences in other underlying claim characteristics.

Other key findings include:

  • Other than regional factors, differences in tenure had the strongest impact on differential CT rates.
  • A review of the CT rates across nine major industry sectors showed that CT claims were most prevalent in the manufacturing sector, where they accounted for nearly half (48.8%) of the litigated claims, which was almost twice the proportion noted in the construction sector.
  • Workers under the age of 30 had a somewhat lower CT rate (28.3%) than workers who are over 30, whose CT rates ranged from 35.1% to 38.8%, though more than a third of all CT claims in the study involved injured workers who were under 40.
  • CT rates were considerably higher for workers at the lower end of the wage scale, with CT rates of 40.0% for workers making less than $300 per week and 42.1% for those earning $300 to $599 per week. In contrast, workers making more than $900 per week all had similar CT rates, with CT claims representing between 30.0% and 31.7% of their litigated claims.

CWCI’s analysis of CT claims, Cumulative Trauma and Litigated Claims in the California Workers’ Compensation System, is available to the public and is available to CWCI members and research subscribers who log in to the Research section of the website.