Factors affecting the first 24-hour mortality of patients receiving emergency medical service (EMS) in a sub-urban area: a retrospective cohort study

Abstract

Background: Saraburi province in central Thailand connects the capital to the north and northeast. A hospital-based model drives the Emergency Medical Service (EMS) system in Saraburi’s vicinity. We studied factors related to death within 24 hours of EMS patients. Methods: Patients who received EMS from the high-level operation team of Saraburi Hospital from 1 May 2017 - 7 July 2019 were enrolled in the study. Various factors that may affect death within 24 hours were collected. Data were analyzed by flexible parametric survival analysis using an exploratory model. Result: Out of 2,321 patients, 118 died within 24 hours. The factors associated with a statistically significant increase in the hazard ratio of death within 24 hours were male sex (aHR, 1.69; 95% CI, 1.05-2.71; p = 0.031), time from symptom onset to calling for medical assistance within two hours (aHR, 3.04; 95% CI, 1.12-8.24; p = 0.029), diastolic blood pressure < 60 mmHg (aHR, 3.21; 95% CI, 1.01-10.21; p = 0.049), pulse < 50 or ≥120 beats/min (aHR, 2.17; 95% CI, 1.00-4.71; p = 0.050), Glasgow Coma Scale ≤ 8 (aHR, 16.16; 95% CI, 6.68-39.11; p < 0.001), transport time >15 min (aHR, 2.02; 95% CI, 1.01-4.03; p = 0.046) and present prehospital life-saving intervention (aHR, 3.52; 95% CI, 1.30-9.51, p = 0.013). Factors associated with a statistically significant decrease in this ratio were the distance from the scene to the hospital >10 km (aHR, 0.35; 95% CI, 0.18-0.71; p = 0.004), and the synchronized operation with the Basic Life Support (BLS) team (aHR, 0.40; 95%CI, 0.20-0.81; p=0.010). Conclusions: The study emphasizes the importance of early intervention, synchronized operations, and access to appropriate levels of care in improving patient outcomes and reducing mortality in patients receiving EMS. Further prospective studies are required to confirm these results.