Statistical analysis
The SPSS statistical package (version 15.0; Chicago, IL) was used for all data analysis. Descriptive findings for categorical variables were reported as number and percentage; nominal variables were reported as mean, standard deviation, minimum, maximum and median. When the nominal variables did not achieve normal distribution, independent group comparison was performed with Mann Whitney U test for 2 groups and with Kruskal Wallis test for more than 2 groups. Dependent group analysis was performed with Wilcoxon test. Spearman correlation analysis was used for relations between nominal variables when parametric test condition was not achieved. Relation formula is investigated with Linear Regression Analysis. A P value of less than 0.05 was considered statistically significant.