Study selection
The inclusion criteria were (a) randomized controlled trials (RCTs), cohort studies, or case-control studies; (b) inclusion of an NIV-NAVA group and a conventional NIV group; (c) study subjects were preterm neonates born at < 37 weeks; (d) the study included infants with respiratory failure of various etiologies who underwent invasive mechanical ventilation > 24 hours after birth; and (e) only compared outcomes of initial elective extubation. Exclusion criteria were (a) case reports, editorials, review articles, letters, and animal experiments; (b) low quality articles with severe experimental design flaws or unclear raw data; and (c) studies that were not original.