Statistical analysis
Statistical analysis was conducted using SPSS (IBM, Amonk, New York,
USA) and Stata Software (Statacorp, LLC, TX, USA; version 15).
Categorical variables were expressed as absolute number and percentages.
Normal distribution of continuous variables was assessed with the
Shapiro-Wilk test. Continuous variables normally distributed were
reported as mean ± standard deviation (SD). Continuous variables not
normally distributed were reported as median and interquartile range
[IQR]. Poisson regression model was used to assess differences
between groups in terms of number of complications (a negative binomial
regression model was not employed due to no overdispersion). Univariate
and multivariate logistic analysis was performed to identify predictors
of a negative/non-regular postoperative course.