Table 1

PCC framework of this scoping review

PopulationExtremely premature infants born before 28 weeks of gestational age
ConceptIdentifying risk factors associated with severe BPD classified by the NICHD definition
RCTs, prospective/retrospective cohort studies or case–control studies
ContextStudies conducted in developed countries
Written in English or Japanese
Exclude congenital airway disease
  • BPD, bronchopulmonary dysplasia; NICHD, National Institute of Child Health and Human Development; PCC, population concept context; RCTs, randomised controlled trials.