Hypoxaemia and mortality in children with lower respiratory infection in low-income and middle-income countries: systematic review and meta-analysis

Summary: Background: Hypoxaemic lower respiratory infections (LRIs) are a leading cause of childhood mortality, with the highest burden in low-income and middle-income countries (LMICs). Hypoxaemia—low peripheral capillary oxyhaemoglobin saturation (SpO 2 )—is a marker of severity, and WHO recommends hospitalisation and oxygen administration for patients with SpO 2 <90%. We aimed to update estimates from a 2015 systematic review and meta-analysis examining the association between hypoxaemia and mortality among children with LRIs in LMICs by incorporating studies published over the subsequent decade and evaluating mortality risk across multiple SpO 2 thresholds.