Clinical trials in surgical patients (aged 18 years and over) in which at least one clinical endpoint was reported were eligible for inclusion. Studies in orthopaedic and plastic surgery and other clean surgery trials were excluded, as were studies that examined infections at catheter sites.
The primary outcome was the incidence of postoperative surgical site infection. The secondary outcome was intra-abdominal infection.
The included studies were of mixed patient populations who underwent clean or contaminated surgery. The surgical populations included patients who were undergoing general surgery, vaginal hysterectomy, laparotomy, mastectomy and caesarean section. The povidone-iodine intervention was usually 10% povidone-iodine in scrub formulation. Chlorhexidine was typically given as 0.5% to 2% in a 70% isopropyl alcohol solution administered as a spray (where reported). Application of povidone-iodine and chlorhexidine were by soap, then scrubbing prior to painting. The definitions of sepsis varied across the studies including reductions in bacterial colonisation, bacterial counts, the presence clinical infection, wound infections and/or separation, haematoma, and seroma.
Two reviewers performed the study selection, but the authors did not state how any disagreements were resolved.