Surgical operations and recovery after anesthesia is a complex process. Studies examining the interventions performed in the preoperative period often focus on classical clinical outcomes such as postoperative organ dysfunction, morbidity or complications. Postoperative recovery of the patient is rarely considered the most important outcome variable in interventional studies.

In this study, the Quality of recovery 15 (QoR - 15) questionnaire that measures the recovery score, and the American college of surgeons surgical risk calculator have been used to compare the predictive values of patient's preoperative condition on postoperative recovery period and possible morbidity and mortality.

Surgical operations and recovery after anesthesia is a complex process. Studies examining the interventions performed in the preoperative period often focus on classical clinical outcomes such as postoperative organ dysfunction, morbidity or complications. Postoperative recovery of the patient is rarely considered the most important outcome variable in interventional studies. In this study, the effects of both preoperative patient condition and postoperative recovery on morbidity and mortality are investigated.

In order to evaluate the ability of QoR - 15 to predict postoperative complications patients who underwent major abdominal surgery, patients answer the Quality of Recovery 15 questionnaire both in the preoperative and postoperative periods.

In addition, the risk of postoperative complications is calculated in the preoperative period with the American college of surgeons (ACS) surgical risk calculator.

Finally, postoperative complications of all patients are recorded according to Clavien Dindo classification.

The primary goal is to understand the predictive value of the QOR15 score on postoperative complications. Secondarily, it is to compare of predictive values of QoR15 with ACS risk calculator on morbidity and mortality. Another secondary aim is to investigate the effect of preoperative conditions of patients on postoperative recovery.

Inclusion Criteria:

All the patients who undergone major GIS surgery

Exclusion Criteria:

1. Patients who has an expected mortality in six months because of the primary disease
2. Patients who received parenteral nutrition before surgery
3. Patients who has a previous major abdominal surgery
4. Patients who do not accept the surgery
5. Patients with a disability who require a nursing care

All the patients who undergone major GIS surgery over age of 18