STATISTICAL ANALYSIS
We used a certified statistical program, MedCalc version 13.1.2. (VAT
registration no. BE 0809 344 640, Member of International Association of
Statistical Computing, Ostend, Belgium), to perform statistical
analyses. Continuous data were compared using the Student’s t-test or
the Wilcoxon rank-sum test as appropriate. The χ2 test
and Fisher’s exact test were used for categorical variables. Univariate
and multivariate logistic regressions were used to assess monitored
parameters in order to predict the risk of severe course and death.
Statistically significant parameters assessed in the univariate analysis
were entered in the multivariate model. Statistically significant
parameters were also further analysed by the means of probit regression.
We considered the P-value of < 0.05 to be statistically
significant.