A retrospective cohort study found that surges in hospital COVID-19 caseload significantly increased mortality in the hardest hit U.S. hospitals. The findings are published in Annals of Internal Medicine.

Researchers from the National Institutes of Health studied data for a nationally representative cohort of 144,116 hospitalized patients cared for in 558 hospitals to understand the effect of COVID-19 surges on patient outcomes. The researchers devised a unique surge index to measure the strain a hospital experienced each month from COVID-19 volume in relation to baseline bed capacity. The surge index not only enabled capture of the potential detrimental effects of overburdened staff during a surge but also highlighted ongoing needs for specific care settings (for example, ICU) and supplies (such as respiratory support devices). The authors also modeled the surge index over time, to provide perspective on how therapeutic advancements influenced outcomes during waves of the U.S. pandemic.

The researcher found that clusters of high-surge index hospitals existed and varied across geography and time. They also found that the use of therapeutics decreased ICU admissions and mechanical ventilation rates, but the surges were still extremely detrimental to clinical outcomes. After risk adjustment, patients cared for in the highest surge strata experienced 2-fold greater mortality than in hospitals not experiencing surges. The data shows that nearly 1 in every 4 deaths and almost 6,000 total deaths may have been attributable to hospital strain due to COVID-19.

As the delta variant of the virus, a serious global threat, continues to become more prevalent, these findings suggest that many COVID-19 deaths may be preventable through prudent public health and healthcare organizational interventions that minimize the effect of surges. The author of an accompanying editorial from the University of Michigan details potential strategies for doing just that. Creating a structure for a coordinated, regional approach could help to absorb the shock of rapid increases in COVID-19 volume. The author says that a focus on staff is also imperative, as surveys show that many are considering leaving the field after being battered by wave after wave of COVID-19.