Normal distribution of the data was assessed by the KolmogorovSmirnov test with Lilliefors’ correction; homogeneity of variances was evaluated using the Levene median test. If both conditions were satisfied, paired ttest was used; otherwise Wilcoxon test was applied. Spearman’s correlation coefficients were used to test the association of variables in CB and PLB. A receiver operating characteristics (ROC) curve was constructed to determine cutoff points between specific
subgroups of patients with different responses to PLB. Subgroups were compared using ttest. All
statistical analyses used the SigmaStat 3.11 software (SYSTAT Software, Inc., Chicago, IL, USA).
Differences were considered significant when p