2.3 Data analysis
Statistical analysis was performed using
IBM®SPSS® Statistics version 26.
Categorical variables are presented as frequencies and percentages, and
continuous variables as means and standard deviations if normally
distributed, or medians and interquartile ranges for variables with
skewed distributions. Normal distribution was verified through the
Kolmogorov-Smirnov test or skewness and kurtosis (maximum tolerated
interval of -1 to 1).
Bivariate analysis was performed by using χ2 test (or Fisher exact test
as appropriate) for categorical variables and t test for continuous
variables. Using logistic regression, odds-ratio (OR) were determined.
All reported p values are two-tailed with values inferior to 0.05
indicating statistical significance.
We also proceeded to analyse the sub-group with a severely prolonged QTc
interval as defined by values greater than 500ms.
The study was approved by the local ethics committee. Due to the
retrospective nature of the study, informed consent from patients was
waived.