Table 1.

PICOS framework (Population, Intervention, Comparator, Outcome, Study Design).

PICOS	Description
Population	Infants and children (excluding newborn children) who are in ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) during out-of-hospital or in-hospital cardiac arrest
Intervention	Initial defibrillation dose approximating 2 J/kg (1.5–2.5 J/kg)
Comparison	Compared with initial defibrillation dose of > 2.5 J/kg, <1.5 J/kg or any other specified dose
Outcomes	Survival to hospital discharge and return of spontaneous circulation (ROSC) were ranked as critical outcomes. Termination of VF/pVT was ranked as an important outcome.
Study Design	Randomised controlled trials (RCTs) and non-randomised studies (non-randomised controlled trials, interrupted time series, controlled before-and-after studies, cohort studies) and case series with a minimum of 5 number of cases were eligible for inclusion. Unpublished studies (e.g., conference abstracts, trial protocols) were excluded. All relevant publications in any language were included as long as there was an English abstract.