PromotIng Optimal Treatment for Community-acquired PNeumonia in EmErgency Rooms

The pathway uses already-ascertained data, bioMérieux Spotfire testing, and POC CRP testing to stratify patients into risk categories. The first step in the pathway will be POC CRP testing; children with CRP \> 60 mg/L will be deemed 'appreciable risk', whereas those with CRP \< 20 mg/L will be deemed 'low risk'. The CRP cut-offs of 20mg/L (more sensitive) and 60mg/L (more specific) were selected after reviewing the literature, with particular emphasis on meta-analyses; other large recent studies have also used 60mg/L as an upper cut-off for bacterial infection. Participants with CRP between 20-60mg/L will be categorized further to identify children either more likely to have bacterial pneumonia or more intolerant of misclassification. 'If they have O2 saturation \<95% AND tachypnoea as per age-specific norms, they will be 'appreciable risk' (\>60 bpm for age \<1 y, \>50 bpm for 1-2 y, \>40 bpm for 2-4 y, and \>30 bpm for \>4 y).

Participants will be recruited in the ED and will be managed as per the treating clinician; the study team will not influence management.