Prehospital Performance of Five Early Warning Scores to Predict Long-Term Mortality in Patients with Suspected Respiratory Infections

<b>Background:</b> Respiratory infections (RIs) are a common cause of care by Prehospital Emergency Medical Services (PEMS). Early Warning Scores (EWS) are tools used by PEMS to assess patients with acute pathology. However, there is little evidence of their application in RIs. The primary aim of this study was to assess the ability of five EWS to predict one-year mortality (M1Y) and two-year (M2Y) mortality in patients with suspected RI assisted by PEMS. The secondary objective was to perform a survival analysis. <b>Methods:</b> An observational and prospective study was conducted in adult patients with RIs transferred by EMS to their referral hospital. The variables necessary for the calculation of EWS [National Early Warning Score 2 (NEWS2), Quick Sequential Organ Failure Assessment (qSOFA) score, Quick COVID-19 Severity Index (qCSI), CURB-65 Score for Pneumonia Severity (CURB-65) and BAP-65 Score for Acute Exacerbation of COPD (BAP-65) score] were collected. The prognostic ability of the EWS was assessed by the area under the receiver operating characteristic curve (AUC). Patients were followed up and a survival study was performed. <b>Results:</b> A total of 819 patients met the inclusion criteria. M1Y was 55.9% and M2Y was 63.5%. BAP-65 showed the best predictive ability at both 1 and 2 years, with AUC of 0.716 and 0.711, respectively. 48.8% of deaths took place during the first month. <b>Conclusions:</b> BAP-65 was the score with the best ability to predict both M1Y and M2Y after the index event in patients with RIs. All other EWS analyzed showed poor performance except in patients with low comorbidity.