2.6. Statistical analysis

Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 22 (Chicago, IL). Categorical data were presented as frequencies and percentages (%). Continuous data were presented as mean ± standard deviation (SD) for normal variables, and non-Gaussian variables were presented as median. All continuous variables were checked for normality using Kolmogorov-Smirnov test. Non-Gaussian variables were log transformed prior to performing parametric analysis. Differences between groups were evaluated using a Student's t test. The relationship between variables was determined using Spearman correlation. A P value of < .05 was considered statistically significant.