Statistical analysis
REGRESSION, EVENTS, COLD, PULMONARY HYPERTENSION
The sample size required for regression modeling can be estimated based on the principle of approximately 10 outcome events per variable that can affect the outcome [For statistical analysis, categorical data were presented as proportions and evaluated with χDLNMs are a modeling tool that describes potentially non-linear and delayed dependencies [Where the subscript Modeling was also performed for subgroups of patients based on gender (male and female); age (≤ 0.3 year, 0.3 to 0.8 year, 0.8 to 2 years, and 2 to 6 years); the season during which the surgery was conducted (warm and cold seasons); BMI (≤ 17 and > 17); risk adjustment for congenital heart surgery (RACHS) classification (≤ 2 and > 2); whether pulmonary hypertension (PH) was present [