Multivariate analyses
We performed multivariate mixed-effects linear models to assess the
associations between the study groups and MME and the Analgesic index
during recovery and discrete and total VAS scores in each time point
after surgery. The models were
adjusted for the number of previous operations, BMI, the patient’s age,
and the length and type (major vs. minor) of surgery, and were clustered
for the surgeon’s identity.
Multivariate mixed-effects logistic models were performed to assess the
risk for the need for analgesic treatment at each time point after
surgery, adjusting for the type of surgery (major vs. minor) and the MME
given during recovery. Those models were also clustered for the
surgeon’s identity.
We also conducted secondary analyses, comparing observations with and
without subcutaneous and intraperitoneal anesthesia. Those analyses were
also performed using both linear and logistic mixed effects models.