Greater ambulance escalation care use associated with higher 28-day mortality

When emergency departments (EDs) exceed capacity, ambulances may be used as escalation areas for patient care. A post-hoc secondary analysis of UNCORKED, a prospective multicentre observational cohort, examined whether the proportion of escalation-care time delivered in ambulances was associated with all-cause 28-day mortality. The study included 18,744 patients aged 16 years or older attending EDs in England, Wales and Northern Ireland in March 2025.

Among 131 EDs using escalation areas, 82 (62.6%) used ambulances for this purpose. Overall, 1,240 patients (6.6%) died within 28 days. Each 5% increase in the proportion of a site's escalation care delivered in ambulances was associated with a 2.1% higher adjusted hazard of death (hazard ratio 1.021, 95% CI 1.002–1.041; p = 0.032).

The findings raise questions about how hospitals manage overflow care during ED crowding, but do not establish that ambulance-based care causes higher mortality. The exposure was measured at hospital level, and unmeasured organisational differences may have confounded the association. The authors describe the findings as hypothesis-generating. The original study was funded by the Royal College of Emergency Medicine; this secondary analysis was unfunded, and the authors declared no competing interests.