Statistical analysis
Categorical variables are expressed in frequency and proportion.
Continuous variables that conformed to the positive distribution are
expressed as mean and standard deviation (SD) values, while continuous
variables that did not conform to the positive distribution are
expressed as median and interquartile range (IQR) values. The
Chi-squared test or Fisher’s exact test was used to analyze the
categorical variables, when appropriate. The Mann–Whitney U test
or independent-samples t test was used to assess the continuous
variables, when appropriate. The area under the receiver operating
characteristic (ROC) curve (AUC) was used to evaluate the discriminative
ability. The AUC varied from 0.5 to 1.0, with 0.5 representing a random
chance and 1.0 representing a perfect fit. Sensitivity, specificity,
PPV, NPV, and accuracy were calculated with a 95% confidence interval
(CI). Statistical analyses were
conducted using SPSS, version 26.0.0.2 (IBM Corporation, Armonk, NY,
USA) and R version 4.2.1
(http://www.R-project.org; The R
Foundation for Statistical Computing, Vienna, Austria). P< 0.05 was considered to be statistically significant.