Four studies (19,014 blood cultures) were included: three randomised controlled trials (RCTs) and one prospective clinical trial. The total number of participants was at least 2,121 (number of participants not reported in one study).
One RCT (1,503 patients) where participants had venipuncture site disinfection treatment with either 10% PI or with a kit containing 2% IT in 47% alcohol produced a total of 376 cultures out of 3,851 with positive results. Contamination rates were 3.8% for the PI group and 2.4% for the IT group (p=0.01).
One RCT (403 patients) included participants who underwent skin preparation with 0.5% chlorhexidine gluconate in alcohol and aqueous, or 10% PI. Out of a total of 2,041 cultures, 124 had positive results. Contamination rates were 1.4% for the chlorhexidine gluconate group and 3.3% for the PI group (p=0.004).
No statistically significant differences were found in one randomised crossover study comparing the effectiveness of 10% PI, 70% IPA and 47% IT in ethyl alcohol with PI and 70% ethyl alcohol, and one prospective clinical trial comparing the effectiveness of two kits, either 2% chlorhexidine in 70% IPA or 2% IT in 47% ethyl alcohol and 70% IPA.
There was evidence of clinical heterogeneity among the studies. In addition, it is unlikely that any of the study investigators were blinded to the interventions.