A Tool to Distinguish Viral From Bacterial Pneumonia

Background: Establishing the etiology of community-acquired pneumonia (CAP) in children at admission is challenging. Most of the admitted children with CAP receive antibiotics. We aimed to build and validate a diagnostic tool combining clinical, analytical and radiographic features to differentiate viral from bacterial CAP, and among bacterial CAP, typical from atypical bacteria. Methods: Design-observational, multi-center, prospective cohort study was conducted in 2 phases. Settings: 24 secondary and tertiary hospitals in Spain. Patients-A total of 495 consecutive hospitalized children between 1 month and 16 years of age with CAP were enrolled. Interventions-A score with 2 sequential steps was built (training set, 70% patients, and validation set 30%). Step 1 differentiates between viral and bacterial CAP and step 2 between typical and atypical bacterial CAP. Optimal cutoff points were selected to maximize specificity setting a high sensitivity (80%). Weights of each variable were calculated with a multivariable logistic regression. Main outcome measures-Viral or bacterial etiology. Results: In total, 262 (53%) children (median age: 2 years, 52.3% male) had an etiologic diagnosis. In step 1, bacterial CAPs were classified with a sensitivity = 97%, a specificity = 48%, and a ROC's area under the curve = 0.81. If a patient with CAP was classified as bacterial, he/she was assessed with step 2. Typical bacteria were classified with a sensitivity = 100%, a specificity = 64% and area under the curve = 0.90. We implemented the score into a mobile app named Pneumonia Etiology Predictor, freely available at usual app stores, that provides the probability of each etiology. Conclusions: This 2-steps tool can facilitate the physician's decision to prescribe antibiotics without compromising patient safety.Instituto de Salud Carlos III (Ministry of Economy, Industry and Competitiveness)Instituto de Investigacion Hospital 12 de Octubre (i+12) AY191212-1Universidad Europea de Madrid 2017/UEM03Instituto Ramon y Cajal de Investigacion Sanitaria (IRYCIS)Spanish GovernmentGrant for emerging groups (PCAPE 2011_0025; 320/11)3.806 JCR (2021) Q1, 31/130 Pediatrics1.104 SJR (2021) Q1, 29/320 Pediatrics, Perinatology and Child HealthNo data IDR 2021UE