2.6 Statistical analysis
Continuous variables were expressed as mean ± standard deviation.
Discrete variables were presented as percentages. Univariate comparisons
among the variables were made using the chi-squared
(χ2) test for categorical variables and the Student’s
t test for continuous variables. A one-way ANOVA followed by
Bonferroni’s post hoc test was performed to evaluate the statistical
differences of variables among the groups for continuous variables.
Pearson correlation analysis was performed for multiple continuous
variables. All tests were two-tailed. P < 0.05 was considered
statistically significant. All statistical analyses were performed by
SPSS (SPSS Inc., version 21.0, Chicago, IL, USA).