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.