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).