2.4 Statistical analysis
Data were summarized as absolute frequency (percentage) for nominal
variables and as mean (standard deviation [SD]) for continuous
variables. Percentages were compared with the Chi-square or Fisher’s
exact test. Continuous data were compared using the Student’s t-test or
Mann-Whitney U-test. Survival curves for DFS and OS were generated using
Kaplan-Meier survival curves and compared using the log-rank test. The
effect of uterine manipulator type on DFS and OS were evaluated using
univariable and multivariable Cox proportional hazards regression
analysis, expressed as hazard ratio (HR) and 95% confidence interval
(CI). The following baseline variables were added as potential
confounders in the multivariable analysis: age at onset, FIGO stage, and
presence of LVSI. Also, the type of hospital (academic versus
non-academic) was added in the multivariable analyses. A p-value of less
than 0.05 was considered significant. Data were analysed with the
statistical package STATA/SE (version 14.1; STATA CORP., College
Station, Texas, USA).