​ANZNN: Confined to infants less than 28 weeks gestation. If more than one form of respiratory support has been provided during the 24 hours prior to undertaking the Shift Test, select that provided immediately prior (Unknown; No respiratory support; Low flow air +/- oxygen with feeds greater than or equal to 1L per minute; Low flow oxygen greater than or equal to 1 litre per minute; Oxygen via head box or incubator; High flow greater than 1 litre per minute; Nasal CPAP; Nasal ventilation includes nasal high frequency; Endotracheal CPAP or ventilation includes high frequency; Endotrocheal tube alone; Tracheostomy CPAP or ventilation includes high frequency; Tracheostomy alone).