Statistical analysis
GraphPad Prism8.0 software (San Diego, CA, USA) was used to analyzed
data. Continuous variables were expressed as standard deviation (SD) or
median and interquartile range (IQR) according normal or non-normal
distribution, respectively. Comparison between two normal distribution
groups was performed by two-tailed unpaired t test
with
Welch’s correction. The correlation of two groups with normal
distribution was computed by Pearson correlation analysis, while
non-normal distribution was calculated by Spearman correlation analysis.
In order to perform the multiple factors correlation analysis, the
variables in the
univariate
analysis with p -value less than 0.10 and no multicollinearity
were included.
Multicollinearity
was judged according to the condition indexes and the variance ratio in
the fitted equation. p -values less than 0.05 were considered
statistically significant.