Changes in health statuses of patients before surgery (preoperative baseline) and again on the second day after surgery (postoperative). Preoperative versus postoperative health statuses, the QoR-15 items of (A) Group S, (B) Group D; and the QoR-15 items of Group S versus Group D, (C) preoperative health statuses, (D) postoperative health statuses. Values are expressed as means (SEM); *P<0.05, **P<0.01. Quality of recovery (QoR)-15 items included the following (14): 1. ‘Able to breathe easy’; 2. ‘Able to enjoy food’; 3. ‘Feeling rested’; 4. ‘Able to sleep well’; 5. ‘Able to look after personal toilet and hygiene unaided’; 6. ‘Able to communicate with family or friends’; 7. ‘Getting support from hospital doctors and nurses’; 8. ‘Able to return to work or usual home activities’; 9. ‘Feeling comfortable and in control’; 10. ‘Having a feeling of general well-being’; 11. ‘Moderate pain’; 12. ‘Severe pain’; 13. ‘Nausea or vomiting’; 14. ‘Feeling worried or anxious’; 15. ‘Feeling sad or depressed’ (each scored on a 11-point numerical rating scale 0–10).