Figure. Screening, Enrollment, Randomization, and Follow-up in the OPTIMIST-A Randomized Clinical Trial.

^aIntubated in the delivery room or shortly after arrival in the neonatal intensive care unit; no continuous positive airway pressure administered.

^bTwo infants were excluded after randomization (1 randomization failure and 1 ineligible because required fraction of inspired oxygen was 0.24).

^cIncludes 6 infants who received active therapy in error (2 incorrect randomization envelope opened and 4 treatment allocation inadvertently not followed). Excludes 4 infants who received control therapy (2 were randomized to active therapy but required intubation immediately after randomization, 1 for whom surfactant instillation catheter was not available, and 1 inadvertently treated as control).

^dIncludes 2 infants who received control therapy in error (randomized to active therapy but surfactant instillation catheter unavailable and treatment allocation inadvertently not followed). Excludes 6 infants who received active therapy in error (2 incorrect randomization envelope opened and 4 treatment allocation inadvertently not followed).