Manley BJ, et al. - This study entailed a determination of the clinical and demographic variables that predict nasal high-flow (nHF) treatment failure when used as a primary respiratory support for preterm infants. Findings displayed that in preterm infants ≥28 weeks' gestational age (GA) enrolled in a randomized, controlled trial, lower GA and higher prerandomization fraction of inspired oxygen (FiO2) predicted early nHF treatment failure. Patients exhibited a greater tendency of being successfully treated with nHF from soon after birth if they were born at ≥30 weeks GA and had a prerandomization FiO2 <0.30. Nevertheless, data disclosed the superiority of continuous positive airway pressure over nHF as early respiratory support in preventing treatment failure.