Light-guided nudging and data-driven performance feedback improve hand hygiene compliance among nurses and doctors

•Doctors (surgeons) have lower baseline hand hygiene compliance than nurses.•Light-guided nudging and data-driven performance feedback improve compliance.•Individual performance feedback might be more effective than group feedback.•The Sani nudge system detects more opportunities than using manual observations.•Nurses and doctors disinfect hands more often after rather than before patient contact.