Statistical analysis
CRF
RECRUITMENT, CRF
In accordance with previously published data, the sample size was calculated as a 30% rate of patients with POD. Therefore, 58 patients in each group were needed to have 80% power at a two-sided alpha level of 0.05The randomization was un-blinded at the end of the patient recruitment. Patient data were stored in a CRF and transferred to a SPSS worksheet (Version 24) for further analysis. BIS data were collected from the BIS Monitor and were stored on an Excel sheet. Continuous variables are reported as mean with standard deviation or interquartile range, when appropriate. Dichotomous variables are reported as numbers with percentages and were compared using the Chi squared test of independence. Non-parametric were analysed using Mann–Whitney U test. Normal distributed categorical variables were analysed with students t-test. Results were statistically significant when p was < 0.05.