Statistical analysis
pain
Individuals who were randomized were known as the intention-to-treat population. Patients with data for the primary endpoint of pain at rest on the 14th POD were known as the per-protocol population. Baseline comparison in age, sex, BMI, operating time, and ASA class between study arms was performed using the chi-square test (with Yates’ continuity correction) and independent t-Test for categorical and continuous variables, respectively. The strength of effects was assessed by Cohen’s d and Cramer’s V.To incorporate the longitudinal design of repeated measurements, a mixed-model analysis was performed in R (version 4.2.3, R Software Foundation) using the lme4-package [The main effects of time and study, as well as an interaction between time and study group were examined. The patient was entered as a random factor in the model. Partial eta-squared (ηp2) was calculated as effect size, indicating the proportion of variance in the dependent variable that can be explained by the independent variable, with values around 0.01, 0.06, 0.14 interpreted as small, medium, and large effects, respectively [