ES. Pitfalls in evidence assessment: the case of chlorhexidine and alcohol in skin antisepsis

Chlorhexidine has attracted increasing attention for its role in skin antisepsis in recent years. It was tested in sev-eral prominent clinical trials and subsequently recommended in important guidelines for blood culture collection, vascular catheter insertion and surgical skin preparation. We noticed and subsequently reported a widespread misinterpretation of evidence surrounding chlorhexidine and its role in skin antisepsis. Multiple clinical trial reports and systematic reviews that had assessed the clinical efficacy of chlorhexidine/alcohol combinations for skin antisepsis had attributed efficacy solely to the chlorhexidine component. This misinterpretation was carried over into the tertiary literature, including evidence-based guidelines. Here we discuss some of the scientific, eth-ical, patient safety and infection control implications of this misinterpretation, as well as broader implications for evidence-based medicine