2.5 Statistical analysis
Descriptive statistics were used to evaluate baseline characteristics of the study population. Continuous variables are presented as means with standard deviations or medians with interquartile ranges and categorical variables as numbers and percentages. We used a multivariable unconditional logistic regression model to calculate the adjusted odds ratio (OR) and 95% confidence interval (CI) for the risk of serious GI complications, considering the study variables. To apply the risk prediction model during multivariate analysis, continuous variables were converted to categorical variables [13].