2.7 Statistical analysis
Data are expressed as percentages for the nominal variables, medians for
the ordinal variables, and means for the continuous variables. Discrete
variables were compared using the chi-square or Fisher exact test as
appropriate. The mean AWT was compared among the 8 segments of the whole
LA groups using a 1-way ANOVA and post hoc analysis with a Tukey
correction for multiple comparisons of data. ROC curves were used to
determine the AWT that provided the best sensitivity and specificity for
the NPAs. A value of p < 0.05 was considered statistically
significant. The correlations
between two parameters were assessed using Pearson or Spearman rank
correlation tests. To assess the proportion of NPAs in each group, a
correction for multiple comparisons was performed. All statistical
analyses were performed using EZR on R commander, version 1.36 software.