4. Statistical analysis
All data were analyzed with SPSS Statistics Software (version 26; IBM,
New York, USA). The statistics for categorical variables were summarized
as frequencies and percentages and were compared using Chi-square test
or Fisher’s exact test between different groups where appropriate.
Continuous variables were described using median (IQR) and compared
using Mann-Whitney U test. To explore the risk factors associated with
disease severity, univariable and multivariable logistic regression
models were used to estimate odds ratios and the 95% confidence
intervals. A two-sided α of less than 0.05 was considered statistically
significant.