Oakland–A new California Workers’ Compensation Institute (CWCI) study finds that the number of California workers’ compensation inpatient hospital stays fell 31.2% between 2008 and 2016, compared to a 19.6% drop in hospital stays paid under private plans, a 2.4% increase in Medicare inpatient stays, and a 19.6% increase in inpatient stays paid by Medi-Cal, which saw a huge jump in enrollment with the rollout of Affordable Care Act (ACA) plans.

To measure and compare the use of inpatient services and procedures in the different systems, CWCI Senior Research Associate Stacy Jones analyzed discharge data compiled by the state Office of Statewide Health Planning and Development on more than 32 million inpatient hospital stays from 2008 through 2016.  Workers’ compensation is the smallest of the four medical delivery systems reviewed, accounting for just 0.5% of all inpatient stays in 2016, which the study notes is down from 0.7% in 2008, primarily due to a surge in Medi-Cal hospitalizations after 3.7 million adult Californians were added to the Medi-Cal rolls once the ACA plans became available in 2014.  The study also shows a steady drop in workers’ comp inpatient stays from 2008 to 2016 as claim volume declined, use of ambulatory surgery centers increased, utilization review and independent medical review programs required that treatment requests meet evidence-based medicine standards, technological and procedural advances allowed more services to be provided in outpatient settings, and the number of spinal fusions fell by 36% after duplicate payments for spinal implant hardware were eliminated from the workers’ compensation  inpatient fee schedule.

In addition to tracking inpatient trends for California workers’ compensation, Medicare, Medi-Cal and private plans over the 9-year span of the study, other analyses and exhibits in the report provide detailed data showing:

• The breakdown of surgical vs. medical (non-surgical) inpatient hospitalizations for each payer group;
• The top 10 inpatient discharges by diagnostic-related group (MS-DRGs) in California workers’ compensation and what percentage of inpatient discharges they represent in the 3 other systems;
• The breakdown of workers’ comp inpatient stays among the top 5 Major Diagnostic Categories (MDCs);
• The distribution of the top 10 workers’ comp discharges involving musculoskeletal MDCs and what proportion of inpatient stays they represent in the other payer groups;
• Changes in the number of implant-eligible spinal surgeries in workers’ comp and in the other systems; and
• The top 10 hospitals based on the share of their inpatient discharges that were covered by workers’ comp.

CWCI has published the results of the study in a CWCI Research Update report, “California Workers’ Compensation Inpatient Hospital Trends.”  Institute members and subscribers can access the report at www.cwci.org and others can purchase it for $21 at the Institute’s online Store.