Statistical analysis
Statistical analysis was carried out using SPSS 21.0 software.
Quantitative data are expressed as mean±SD and were compared with
2-sample t tests for independent samples, whereas dichotomous variables
were reported as absolute values and proportions. Differences in
proportion were compared with a χ2 test or Fisher exact test as
appropriate. Univariate analysis was performed with the Kaplan–Meier
test and with the Cox regression analysis. For each variable, the odds
ratio (OR), 95% confidence interval (CI), and P value were provided.
Variables significantly associated with occurrence of delirium event
after univariate analysis (P<0.05) were entered in a
multivariable logistic regression model to identify the independent
predictors. Additionally, we calculated the area under receiver
operating characteristic (ROC) curve to assess the predictive value of
SAS score for risk of delirium in patients following OPCABG.