Statistical analysis
ADVERSE EVENTS
In this trial, the sample size was estimated for an α level of 0.05 and 90% power in order to detect a 10% difference in the occurrence between groups. On the basis of the preliminary results, the incidence of adverse events after surgery was indicated to be 50% in the routine care group, and we calculated that a sample of 55 patients would provide 90% power to reduce it to 25% [