RESUMEN
Introduction: Ambulance requests by general practitioners for primary care patients (GP-requested) are often omitted in studies on increased demand within emergency care but may comprise a substantial patient group. We aimed to assess acute severity, intensive care unit (ICU) admission, and diagnostic pattern, including comorbidity, and mortality among GP-requested ambulance patients, compared to emergency call ambulance patients. Our hypothesis was that emergency call patients had more severe health issues than GP-requested ambulance patients. Methods: Historic population-based cohort study of ambulance patients in the North Denmark Region, 2016-2020. Hospital contact data including diagnoses, ambulance data, vital signs and vital status was linked using each patient's unique identification number. Primary outcome measure was mortality within 1, 7, and 30 days. Secondary outcomes were disease severity expressed as modified National Early Warning Score (NEWS2), and ICU admission. Admission status and hospital diagnostic pattern, including comorbidity were described and compared. Results: We included 255,487 patients. GP-requested patients (N = 119,361, 46.7%) were older (median years [IQR] 73 [58-83] versus 61 [37-76]) and more had moderate/severe comorbidity (11.9%, N = 13,806 versus 4.9%, N = 6145) than the emergency call patients. Prehospital mNEWS2 median scores were lower for GP-requested patients. For both groups, mNEWS2 was highest among patients aged 66+. GP-requested patients had higher 30-day mortality (9.0% (95% CI: 8.8-9.2), N = 8996) than emergency call patients (5.2% (95% CI: 5.1-5.4), N = 6727). Circulatory (12.0%, 11,695/97,112) and respiratory diseases (11.6%, 11,219/97,112) were more frequent among GP-requested patients than emergency call patients ((10.7%, 12,640/118,102) and (5.8%, 6858/118,102)). The highest number of deaths was found for health issues 'circulatory diseases' in the emergency call group and 'other factors' followed by "respiratory diseases" in the GP-requested group. Conclusion: GP-requested patients constituted nearly half of the EMS volume, they were older, with more comorbidity, had serious conditions with substantial acute severity, and a higher 30-day mortality than emergency call patients.
RESUMEN
Importance: Early warning scores (EWSs) are designed for in-hospital use but are widely used in the prehospital field, especially in select groups of patients potentially at high risk. To be useful for paramedics in daily prehospital clinical practice, evaluations are needed of the predictive value of EWSs based on first measured vital signs on scene in large cohorts covering unselected patients using ambulance services. Objective: To validate EWSs' ability to predict mortality and intensive care unit (ICU) stay in an unselected cohort of adult patients who used ambulances. Design, Setting, and Participants: This prognostic study conducted a validation based on a cohort of adult patients (aged ≥18 years) who used ambulances in the North Denmark Region from July 1, 2016, to December 31, 2020. EWSs (National Early Warning Score 2 [NEWS2], modified NEWS score without temperature [mNEWS], Quick Sepsis Related Organ Failure Assessment [qSOFA], Rapid Emergency Triage and Treatment System [RETTS], and Danish Emergency Process Triage [DEPT]) were calculated using first vital signs measured by ambulance personnel. Data were analyzed from September 2022 through May 2023. Main Outcomes and Measures: The primary outcome was 30-day-mortality. Secondary outcomes were 1-day-mortality and ICU admission. Discrimination was assessed using area under the receiver operating characteristic curve (AUROC) and area under the precision recall curve (AUPRC). Results: There were 107â¯569 unique patients (52â¯650 females [48.9%]; median [IQR] age, 65 [45-77] years) from the entire cohort of 219â¯323 patients who used ambulance services, among whom 119â¯992 patients (54.7%) had called the Danish national emergency number. NEWS2, mNEWS, RETTS, and DEPT performed similarly concerning 30-day mortality (AUROC range, 0.67 [95% CI, 0.66-0.68] for DEPT to 0.68 [95% CI, 0.68-0.69] for mNEWS), while qSOFA had lower performance (AUROC, 0.59 [95% CI, 0.59-0.60]; P vs other scores < .001). All EWSs had low AUPRCs, ranging from 0.09 (95% CI, 0.09-0.09) for qSOFA to 0.14 (95% CI, 0.13-0.14) for mNEWS.. Concerning 1-day mortality and ICU admission NEWS2, mNEWS, RETTS, and DEPT performed similarly, with AUROCs ranging from 0.72 (95% CI, 0.71-0.73) for RETTS to 0.75 (95% CI, 0.74-0.76) for DEPT in 1-day mortality and 0.66 (95% CI, 0.65-0.67) for RETTS to 0.68 (95% CI, 0.67-0.69) for mNEWS in ICU admission, and all EWSs had low AUPRCs. These ranged from 0.02 (95% CI, 0.02-0.03) for qSOFA to 0.04 (95% CI, 0.04-0.04) for DEPT in 1-day mortality and 0.03 (95% CI, 0.03-0.03) for qSOFA to 0.05 (95% CI, 0.04-0.05) for DEPT in ICU admission. Conclusions and Relevance: This study found that EWSs in daily clinical use in emergency medical settings performed moderately in the prehospital field among unselected patients who used ambulances when assessed based on initial measurements of vital signs. These findings suggest the need of appropriate triage and early identification of patients at low and high risk with new and better EWSs also suitable for prehospital use.