Statistical analysis
Data obtained from the study was coded and entered using the statistical package SPSS version 16. The mean values, standard deviation (SD) and ranges were then estimated for quantitative variables, as for the qualitative variables, the frequency distribution was calculated. Comparisons between exposed and control groups were done using the independent simple t-test. The correlations between individual variables were calculated using Pearson correlation coefficient. Ρ Values less than 0.05 and less than 0.005 were considered statistically significant and highly significant, respectively.