Population characteristics for all patients and the two age sub-groups of neonates and older children.

All of the variables from the columns ‘All Patients’ were entered into the propensity score. the PRISM score was not used for the propensity score. Neonates are ≤28 days and older children >28 days and less than 8 years. *p value <0.05 for the difference between the atropine and non-atropine groups. NRD - neonatal respiratory distress, Non-NRD - non-neonatal respiratory distress, ENT - ear nose and throat, PRISM - Paediatric RISk of Mortality score.