To the Editor It was with great interest that we read the article by Meneses et al.1 After reading the article carefully, we have 2 questions. In the review and meta-analysis, Meneses et al concluded that it is plausible that nasal intermittent positive-pressure ventilation (NIPPV) may reduce the incidence of bronchopulmonary dysplasia (BPD) as compared with nasal continuous positive airway pressure (NCPAP). The data were obtained from 3 trials. We noticed that 1 of the trials by Meneses et al2 reported that the total number of infants was 200, 100 in each arm who were randomly assigned. However, Figure 4 (incidence of BPD) of their meta-analysis1 showed that the total number in the NIPPV group was 83, and the total number in the NCPAP group was 80. Why are the total numbers in the 2 articles not consistent? Also, in the meta-analysis,1 Meneses et al chose the number of infants who had moderate or severe BPD but excluded mild BPD. The results of the incidence of BPD showed no significant difference between the groups (risk ratio, 0.56; 95% CI, 0.09-3.49), but significant heterogeneity was found among the trials (P = .04; I2 = 69%). We suggest that all the infants who had BPD (mild, moderate, and severe) should be included for meta-analysis. The results from this meta-analysis (Figure) showed that there was still no difference between the groups (risk ratio, 0.50; 95% CI, 0.13-2.00), and no significant heterogeneity was found among the trials (P = .09; I2 = 58%) in the random-effect model. There was a trend of a relatively low rate of BPD in infants randomized to NIPPV as compared with NCPAP in our meta-analysis. Why did Meneses et al exclude infants who had mild BPD?
Wang L, Shi Y. Questions Concerning Nasal Intermittent Positive-Pressure Ventilation vs Nasal Continuous Positive Airway Pressure. JAMA Pediatr. 2013;167(9):872–873. doi:10.1001/jamapediatrics.2013.2208