Olfactory Cues and Patient Safety Behavior in Virtual Reality Medical Simulation: Controlled Trial.

Background: Simulation-based medical education is essential for improving patient safety. In virtual reality (VR)-based simulation, immersion is primarily generated through visual and auditory cues, while other sensory modalities are typically absent. This sensory limitation may reduce the emergence of authentic safety-relevant behaviors. Olfaction plays an important role in clinical reasoning, risk perception, and self-protective behavior and is closely linked to memory and emotion. Although olfactory cues have been shown to influence hand hygiene behavior in real or simulated environments, their targeted integration into fully immersive VR-based medical simulation has not been systematically examined. Objective: This study aimed to investigate whether adding a real olfactory cue (disinfectant scent) to a fully virtual clinical simulation increases patient safety-relevant behavior, specifically hand hygiene compliance (hand disinfection and glove usage). Methods: In a controlled study at the University of Münster (during the winter term 2025-2026), 95 medical students participated in a VR-based clinical simulation. Study rooms were preassigned to either an olfactory intervention or a control condition, and participants selected their room without knowledge of the assigned condition (quasi-random allocation by room). Hand hygiene and glove use were automatically tracked as outcomes. Odds ratios (ORs) were calculated to assess the effect of the intervention on these behaviors. Results: The olfactory intervention nearly tripled the odds of hand disinfection (8/43, 18.6% vs 20/52, 38.5%; an absolute risk increase of 19.9 percentage points; OR=2.73, 95% CI 1.09-7.40; Conclusions: The integration of a real olfactory cue into a fully immersive VR medical simulation significantly increased hand disinfection behavior, particularly after patient contact, but did not affect glove use. These findings suggest that olfactory augmentation can selectively reinforce safety-relevant behaviors in digital training environments. Incorporating real-world sensory cues into VR may represent a simple yet effective design strategy to enhance behavioral authenticity and patient safety outcomes in simulation-based medical education.