Fig. 4From: Irrigation techniques used in spine surgery for surgical site infection prophylaxis: a systematic review and meta-analysisComparison between povidone-iodine (only RCT and prospective cohort studies) versus controls in their association with SSIs. Legends: PVPI, povidone-iodine; RCT, randomized clinical trials; CI, confidence interval; M-H, Mantel–HaenszelBack to article page