Statistical analysis
Data are presented as mean ± SD or N (%). Student’s t -test andx 2 test was performed to compare the difference between two groups in continuous variables and categorical variables. The differences among three groups were analyzed using one-way ANOVA. ROC (receiver operating characteristic) curves were calculated with AUC (area under curves) estimation for predictive analysis. The Pearson linear correlation analysis was used to estimate the relationship between C t value and feasible parameters. We considered a P -value less than 0.05 as statistically significant. We used Graph Pad Prism version 5.0 to chart. All statistical analyses were performed using SAS 9.4 software (SAS Institute, Cary, NC) (*P < 0.05, ** P < 0.01, *** P< 0.001).