RESULTS
Statistical Analysis
Continuous variables are expressed as means values with standard deviation and the proportions as percentages. The differences between the groups for the categorical variables were compared with chi square or Fisher’s exact test and continuous variables with unpaired Student’s t test or nonparametric test (Kruskal Wallis). A p value of less than or equal to 0.05 was considered statistically significant. Statistical analysis was performed using SPSS, version 11, Chicago, IL.