In this study, investigators aimed to develop and validate a risk score to predict severe outcomes (e.g., mortality and ICU admission) in children who were admitted to the Children's Hospital of Fudan University between 2017 and 2022 due to community-acquired pneumonia (CAP). The objectives were as follows.

1. Develop a risk prediction model based on demographic, comorbidity, clinical characteristics, laboratory data, and chest radiographic reports to predict severe outcomes among children hospitalized with CAP;
2. Develop a risk scoring system and determine the cut-off point;
3. Externally validate the easy-to-use risk score.

Inclusion Criteria:

1. Aged between 29 days and 18 years old;
2. Admitted to hospital with signs or symptoms of acute infection (eg, fever) and acute respiratory illness (eg, cough), and radiographic evidence of pneumonia.

Exclusion Criteria:

1. Pneumonia developed 48 hours after admission or intubation;
2. Chronic pneumonia, tuberculosis, tracheobronchial foreign bodies, aspiration pneumonia, parasitic lung disease, and diffuse pulmonary interstitial/parenchyma disease.

This was a retrospective cohort study of children aged between > 29 days and 18 years old who were admitted to the Children's Hospital of Fudan University in Shanghai, China from January 1, 2017 to December 31, 2022. Children were enrolled if they were hospitalized with signs and symptoms of lower respiratory tract infection and radiographic evidence of pneumonia.