Objective: During the COVID-19 pandemic, the U.S. public was encouraged to practice good hand hygiene, such as hand washing or the use of hand sanitizer. Young adults reported lower levels of hand hygiene compared to adults of other ages. The aim of the current study was to test the effectiveness of different messages to promote hand sanitizer use among young adults.

Method: Over a 6-week period, we examined whether 3 brief messages (gain-frame, static descriptive norms, dynamic descriptive norms), placed next to sanitizer dispensers in university residence halls, predicted dispenser use in comparison to dispensers with no sign. Amount of sanitizer usage was measured 3 times per week via the weight of dispenser units. We tracked and controlled for the number of positive COVID-19 cases in residence halls because we expected it might influence sanitizer usage.

Results: Compared to no signage, dispensers with signs had 35% greater usage, with the static descriptive norms sign associated with greatest usage (46% compared to no sign), although differences did not reach conventional levels of significance. The strongest predictor of sanitizer use was a residence hall’s degree of COVID-19 risk based on the hall’s case positivity.

Conclusions: Dispensers with signs had higher use than those without signs, but this difference was not statistically significant. We conclude that compared to prior research, 'nudges' such as evidence-based messaging may have had less of an effect on health behavior engagement due to methodological differences across studies or characteristics of the COVID-19 context.