2.5 Statistical analysis
Patient characteristics were presented as mean ± SD for continuous
variables with normal distribution and categorical variables presented
as a percentage. Continuous variables were examined using the student’s
t-test. Categorical variables were compared using the chi-square test.
Data were analyzed using the Statistical Package for Social Sciences
(IBM SPSS Chicago, USA, version 22). In all analyses, the alpha level
was set to 0.05.