Table 2.

Summary of included studies

ASA, American Society of Anaesthesiology; CDC, Centre for Disease Control and Prevention; NNIS, National Nosocomial Infection Surveillance; NS, not stated; OPCAB, off-pump coronary artery bypass; SSI, surgical site infection.

^a)POSSUM (physiological and operative severity score for enumeration of mortality and morbidity) score was developed to predict post-operative mortality and morbidity rates. ^b)Includes surgery of the colon, rectum, small bowel, hepato-biliary-pancreas, stomach and appendix. ^c)Includes orthopaedic surgery, plastic surgery, general surgery, neurosurgery, chest surgery, obstetrics and gynaecology, otolaryngology and ophthalmology. ^d)Includes cardiac, colon and gastric surgery, hysterectomy, hip/knee replacement surgery.