The 36.2 % drop in the number of inpatient hospitalizations involving California injured workers over the past decade was largely due to the ongoing decline in spinal fusions and a more recent decline in lower extremity joint surgeries, according to a study released Tuesday by the California Workers’ Compensation Institute.

Researchers with the Oakland-based institute reviewed discharge data compiled by the Office of Statewide Health Planning and Development on 35.9 million inpatient hospital stays from 2010 through 2019 paid by workers compensation, Medicare, the state’s Medi-Cal program and private insurance, in order to identify workers comp inpatient trends.

The study showed that over the 10-year span the number of workers comp inpatient hospitalizations declined 36.2% drop, compared with a 15.9% decline in private coverage, a 4% increase in Medicare, and a 14.5% increase in Medi-Cal hospitalizations. 

Researchers noted that workers comp is the smallest of the medical delivery systems reviewed, accounting for just 0.4% of all inpatient stays in 2019, “which is not surprising given that it has only accounted for between 1.4% and 1.6% of California health care costs over the past decade.”

The study found that a key factor leading to the reduction of worker comp inpatient stays was the sharp decline in the number of injured workers receiving spinal fusions, which fell 53.1% between 2010 and 2019. This decline was spurred by multiple factors highlighted in the report, including the adoption of utilization review and independent medical review programs requiring that treatment meet evidence-based medicine standards, the elimination of duplicate payments for implantable devices used in spinal surgeries, and fraud convictions that led to the sale of hospitals that had a high volume of workers comp back surgeries. 

At the same time the overall number of work injury claims declined and there were technological and procedural advances that allowed more services to be provided in outpatient settings, according to the study.

The study also stated that spinal fusions were not the only type of workers comp inpatient hospitalizations that saw a significant decline, as the number of workers comp discharges associated with lower extremity joint replacements fell from 2,727 in 2014 to 2,140 in 2019, a net decrease of 21.5%.