Study Examines California Workers’ Comp Hospital Inpatient Stays

The number of California workers’ compensation inpatient hospital stays fell 1.9 percent between 2017 and 2018, for a net decline of nearly 31 percent since 2010, a new study shows.

A study from the California Workers’ Compensation Institute traces much of that drop to a declining number of hospitalizations related to musculoskeletal disorders, including spinal fusions.

The CWCI study compares California inpatient hospitalizations paid under workers’ comp, Medicare, Medi-Cal and private coverage using discharge data on nearly 32.3 million inpatient hospital stays with 2010-2018 discharge dates, compiled by the state Office of Statewide Health Planning and Development.

Workers’ compensation is by far the smallest of those systems, and accounted for only 0.4 percent of all discharges in 2018, but inpatient care can be one of the most costly elements of a work injury claim, according to CWCI.

The latest tally of California inpatient discharges by payer group shows that the volume of inpatient hospitalizations decreased less than 2 percent for each of the four payer systems from 2017 through 2018.

Over the nine-year study period, however, workers’ compensation inpatient stays registered the biggest percentage decline, falling by 30.7 percent from 2010 through 2018. That compares to a 14.8 percent drop for private plans, a 2.1 percent increase for Medicare, and a 16.0 percent increase for Medi-Cal largely due to the dramatic expansion of the program under the Affordable Care Act in 2014 and the absorption of California’s Healthy Families Program, which added an estimated 900,000 children onto the Medi-Cal rolls.

A review of the Major Diagnostic Codes associated with the workers’ comp hospital stays shows that musculoskeletal and connective tissue diseases and disorders are by far the most common diagnostic categories, accounting for nearly two-thirds of all injured worker inpatient discharges between 2010 and 2018.

This is not surprising given the prevalence of back, joint, and soft-tissue injuries in workers’ comp, according to the CWCI study.

The study also notes the key difference between workers’ comp hospitalizations and those paid for by other systems is the ratio of surgical to medical stays. In 2018, surgical stays comprised nearly 70 percent of injured workers’ inpatient discharges, but only 26 percent of the inpatient discharges in Medicare, 22 percent in Medi-Cal, and less than 37 percent of all hospitalizations paid under private coverage, according to the study.

The full study is available on CWCI’s website. It’s free for CWCI members and there’s a fee for nonmembers.