Statistical Analysis:
Perinatal and peri-extubation characteristics were compared between those who failed the first extubation attempt and those who were successful. Categorical variables between the two groups were compared using chi-squared or Fisher’s exact tests, and continuous variables were analyzed using Wilcoxon rank sum tests. Logistic regression analysis was performed to determine associations between perinatal and peri-extubation characteristics, including PDA, with success of extubation. Variables in the logistic regression analysis were selected based on a backward selection method (all covariates were initially included, and then nonsignificant covariates were removed if the P value was >0.2). Statistical analysis was conducted using Stata version 16.1 (StataCorp, College Station, TX).