Correspondence Re: High-Flow Nasal Cannulae in Very Preterm Infants after Extubation

To the Editor: In the study by Manley et al., the authors express a degree of caution, but we are concerned that this study will be interpreted as supporting the use of high-flow nasal cannulae. The statement of equivalence assumes that a 20% increase in extubation failure is clinically acceptable, nearly doubling the rate from 25% to 45%. The estimate from the trial is that the use of high-flow nasal cannulae is inferior to CPAP, with an absolute increase of 8.4% and a relative increase of 33.6% in the extubation failure rate, and the authors acknowledge that the upper limit of the 95% confidence interval was close to the already very generous equivalence limit. The article offers no justification for accepting such a large noninferiority margin, although a more clinically acceptable margin would require a substantially larger trial. We believe that this trial offers no evidence in favor of the use of high-flow nasal cannulae and that larger trials that are powered to eliminate meaningful differences in outcomes are required.