Comments on abstract, title, references

• This is a randomized, multicenter trial, with a 2-by-2 factorial designs, involving infants who were born between 24 weeks 0 days and 27 weeks 6 days of gestation. It aimed clearly to compare early CPAP treatment with early surfactant treatment in those extremely preterm infants.The results of this study support consideration of CPAP as an alternative to intubation and surfactant in preterm infants.
• The title informative and relevant but more details about design could be added.
• Abstract are generally well-written and clear but the main aim could have been mentioned more clearly.
• The references are relevant, recent and referenced correctly. The appropriate key studies are included.

Comments on introduction/background

The introduction is clear for what is already known about this topic and the research question is clearly outlined. The research question justified given what is already known about the topic.

Comments on methodology

The process of subject selection is clear and the variables defined and measured appropriately. The study methods are valid and reliable. There is enough detail in order to replicate the study.

Comments on data and results

The data were presented in an appropriate way. Tables and figures are relevant and clearly presented. All are clear about what is a statistically significant result. All are clear about what is a practically meaningful result.

Comments on discussion and conclusions

The results were discussed from multiple angles and placed into context without being overinterpreted. Conclusions answered the aims of the study and were supported by references or results.