Trends in Urgency Levels and Risk of Acute Critical Condition Among Prehospital Patients. A Seven-Year Observational Historic Register-Based Cohort Study

Trends in Urgency Levels and Risk of Acute Critical Condition Among Prehospital Patients. A Seven-Year Observational Historic Register-Based Cohort Study Background : In our region, as in Western countries, the number of emergencies requesting an ambulance is increasing. Whether this may be due to increased disease burden and/or lower threshold for calling is not clear. This study aimed to examine the development over the years in the number and urgency levels of ambulances and the actual acute disease severity, as indicated by initial vital signs measured on scene, together with patient demographics, comorbidity, and mortality trends over time. Methods : We conducted a registry-based observational cohort study of patients aged ≥ 18 years assigned an ambulance in the North Denmark Region from 2017 to 2023. The primary outcomes were urgency level and acute critical severity, assessed by a modified National Early Warning Score. Linear regression was applied to examine for alignment between trends in urgency level over the years and critically versus non-critically severity in prehospital patients assigned to urgency level A (most urgent, potentially life-threatening) and B (less urgent), respectively. Results : Among 202,746 prehospital patients, the proportion assessed as urgency level A decreased from 62% to 59%, while urgency level B increased from 38% to 41%. While the proportion of patients in acute critical condition was 16% vs 8% among level of urgency A and B, and stable during the period, the number of patients in acute critical condition increased by 3.6 (95% confidence interval (CI) 0.7–6.6) and 6.1 (95% CI 4.4–7.8) per quarter. Across the total population, patient age increased from 64 to 66 years, and the proportion with severe comorbidity increased from 11% to 14%. Conclusion : From 2017 to 2023, the number of patients assigned with an ambulance through 1-1-2 increased, as did patient age and comorbidity. During the years were similar proportions of acute critical severity, but increasingly more among urgency level B. Thus, the acute severity among prehospital patients has not diminished. The lack of alignment between the level of urgencies and the acuity severity found on scene should be monitored carefully, together with mortality and clinical outcomes.