2.7 | Statistical analysis
Data were expressed as mean ± SD for normally distributed variables or as median [IQR] for skewed variables. The differences between groups were assessed by using independent Student´s t test (for normally distributed variables) or Mann-Whitney test (for skewed variables). Percentages were used to summarize the categorical variables. Pearsonx2 test was used to analyze the differences between groups for categorical variables. As a non-inferiority trial, all analyses were performed by per-protocol sets. The significant level was set at P <0.05. All analyses were performed by using statistical program IBM SPSS software (Version 25.0).