"Normally and abnormally distributed quantitative variables were compared using the Student's t ‐test and the Mann‐Whitney U test, respectively. Categorical variables were compared using the chi‐squared test. The results were given as the mean ± standard deviation, median (interquartile range), or number (percentage), wherever appropriate. Categorical and consecutive variables were evaluated by logistic regression analysis for their ability to predict 28‐day mortality. A P value of < .05 was considered statistically significant. Data were analyzed using SPSS 21.0 for Windows (SPSS Inc)."