LAUSR

Also, the sample size has been calculated assuming the incidence of primary outcome as 64%. However in this trial, the actual incidence of only 25% was observed in the control group. Had the sample size been calculated from this incidence, a much higher sample of 2188 was required for the above-specified effect size and power. It would be useful if the authors can provide the reason for this huge difference in outcome during the study period from previous year data; whether it is the result of some change in essential newborn practices and ventilator strategies or a part of some quality improvement project? 2. Another concern is that the total duration (median as well as the inter-quartile range) of CPAP and oxygen requirement is much less as compared with the incidence of oxygen requirement at 28 days. Whether this total duration of oxygen requirement included the days on mechanical ventilation or on CPAP?