Physiological BPD [42] | Duration of intubation (all episodes) |
Clinical BPD (oxygen or positive pressure support at 36 weeks corrected gestation) [45] | Duration of CPAP/NIPPV (all episodes) |
Mild/moderate/severe BPD [45] | Duration of intubation and CPAP |
Death | Duration of HFNC, minimum flow rate 2 L/min |
Death or BPD (clinical definition) | Duration of respiratory support |
Intraventricular haemorrhage (IVH) (all grades) | Duration of oxygen therapy |
IVH grades III and IV [46] | Requirement for oxygen at home |
Cystic periventricular leukomalacia | Length of stay in intensive care |
Retinopathy of prematurity (ROP) > stage II | Length of hospital stay |
Major morbidity (any of IVH grade III or IV, periventricular leukomalacia, ROP > stage II, physiological BPD) [47] | Total hospital billings |
Death or major morbidity | Calculated cost of hospitalisation |
NEC (Modified Bell stage 2 or greater) [48] | Pneumothorax requiring drainage |
NEC or spontaneous intestinal perforation requiring surgery | Pulmonary haemorrhage |
Requirement for intubation < 72 h | Patent ductus arteriosus (PDA) requiring anti-prostaglandin therapy |
Requirement for intubation at any time | PDA requiring ligation |
Need for additional surfactant therapy | Late onset sepsis (positive bacterial or fungal culture from a normally sterile site) |
Overall number of surfactant doses (including that given by MIST) | Time to regain birth weight |