2.3. Statistical Analysis
Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS Inc. Chicago IL, USA) v. 15.0. Number, percentage (%), median, and mean ± standard deviation values were used to define data. The normal distribution of data was tested with the Kolmogorov-Smirnov test. Student’s t-test was used to compare normally distributed data, the Mann-Whitney U test to compare non-normally distributed data, and Pearson’s chi-square or Fisher’s test to compare categorical variables. The univariate and multivariate logistic regression analyses were undertaken to determine the relationship between the presence of the source of infection and clinical risk factors in thoracic and abdominal CT. Variables with a p value of <0.1 in the univariate logistic regression analysis were included in the multivariate logistic regression analysis. A p value of <0.05 was considered significant in all comparisons.