It was hypothesized that low‐tie ligation would decrease the rate of anastomotic leakage from 15 to 6 per cent. Using a power of 80 per cent and α of 0·05, a sample size of 362 patients was needed. A dropout rate of approximately 10 per cent was anticipated. Therefore, 400 patients had to be included in this study. Enrolment was scheduled for 5 years after inclusion of the first patient.
Data were analysed according to the intention‐to‐treat principle. SAS® software version 9.2 for Windows® (SAS Institute, Cary, North Carolina, USA) was used for statistical analysis.
Categorical variables are presented as frequencies and percentages. Continuous variables are presented as mean(s.d.) values. The χ2 test and Student's t test were used to compare categorical and continuous variables respectively. Survival was analysed by the Kaplan–Meier method, and the difference between high‐ and low‐tie ligation was analysed with the log rank test. Risk factors for anastomotic leakage were assessed by logistic regression using a forward method. Variables with P < 0·100 were entered into multivariable analysis. P < 0·050 was considered statistically significant. All analyses were two‐sided.
Data were analysed according to the intention‐to‐treat principle. SAS® software version 9.2 for Windows® (SAS Institute, Cary, North Carolina, USA) was used for statistical analysis.
Categorical variables are presented as frequencies and percentages. Continuous variables are presented as mean(s.d.) values. The χ2 test and Student's t test were used to compare categorical and continuous variables respectively. Survival was analysed by the Kaplan–Meier method, and the difference between high‐ and low‐tie ligation was analysed with the log rank test. Risk factors for anastomotic leakage were assessed by logistic regression using a forward method. Variables with P < 0·100 were entered into multivariable analysis. P < 0·050 was considered statistically significant. All analyses were two‐sided.