The health care system has undergone major changes in the past decade, and emergency department (ED) crowding has worsened over time; however, the most recent patterns in ED capacity and use in California have yet to be studied.

Given this increased burden on EDs, ensuring a sufficient supply of ED resources is important, particularly for California, which ranked ninth in the nation in 2022 for states with the longest ED waiting times, with a median waiting time of 164 minutes. Crowding in the ED is a substantial concern because it has been associated with increased mortality, longer lengths of stay, and clinician error.

So researchers from the University of California San Francisco decided to investigate how have emergency department (ED) capacity and use changed in California since 2011, and has the supply of acute care resources kept up with the demand for ED care?

This retrospective cohort study used data from the California Department of Health Care Access and Information and the US Census Bureau to analyze ED facility characteristics from more than 400 general acute care hospitals with more than 320 EDs in California as well as patients who presented to those EDs between January 1, 2011, and December 31, 2021.

The study was published Thursday in the Journal of the American Medical Association Network Open, and it found that statewide, emergency departments and hospital beds both declined, by 3.8% and 2.5%, respectively, over the 10-year period. At the same time, the number of annual visits to ERs grew by 7.4%, from 12.1 million to 12.9 million. The number of annual visits for severe conditions shot up in particular, by 68%, from 2 million to 3.4 million.

The decrease in the number of EDs from 2011 to 2021, may be a result of facility closures and/or hospital consolidation. Closures of EDs are often a symptom of insufficient hospital funding, and staffing shortages have also been cited as a major challenge in keeping EDs open.

With a greater number of sick days and higher rates of burnout among nurses, technicians, and other staff, the strain on EDs has worsened in recent years.

In contrast, the number of ED treatment stations and treatment stations per 1 million people increased over the study period, revealing somewhat conflicting results regarding overall changes in capacity. However, this expansion has happened within a smaller number of total EDs, meaning that certain geographic areas have seen their access to emergency care wane while other areas have seen it expand.

A previous study found that most ED expansion has been localized in affluent (or more commercially insured) areas, supporting the idea that increased ED capacity has not occurred evenly across all populations.

When examining facilities by ownership, we found that not-for-profit hospitals were consistently the most common type of hospital in California, while the number of government-owned hospitals decreased over time. This finding is consistent with results from a study of previous patterns in ownership, which found that nationally, public hospitals have closed at a faster rate than private hospitals, mainly due to the government’s financial constraints after the 2008 recession.

This pattern is particularly concerning because public hospitals are major sources of safety net care, and closures have been associated with decreased access to care and worse overall health among patients in surrounding communities.