Perception of slipperiness and prospective risk of slipping

Background: Falls are a leading cause of injury, and slipping is the predominant cause of falling at work. Prior research has suggested modest correlations between objective (such as coefficient of friction, COF) and subjective measures of slipperiness (such as worker perceptions). However, the degree of association between subjective measures and the actual risk of slipping in the workplace is unknown. We examined the association between perception of slipperiness and the risk of slipping. Methods: 475 workers from 36 limited-service restaurants participated in a 12-week prospective-cohort study. At baseline, demographic information was collected, participants rated floor slipperiness in eight areas of the restaurant, and work environment factors such as COF were measured. Restaurant-level and area-level mean perceptions of slipperiness were calculated. Participants then reported their slip experience at work, weekly, for the next 12 weeks. Associations between perception of slipperiness and the rate of slipping were assessed. Results: Adjusting for age, gender, BMI, education, primary language, mean COF, use of slip-resistant shoes, and restaurant chain, each 1 point increase in mean restaurant-level perception of slipperiness (4 point scale) was associated with a 2.71 times increase in the rate of slipping (95% CI 1.25-5.87). Results were similar for area-level perception within the restaurant (RR 2.92, 95% CI 2.41-3.54). Conclusions: Perception of slipperiness and the future rate of slipping were strongly associated. These findings suggest that public and occupational health professionals, risk managers and employers could utilize aggregated worker perceptions of slipperiness to identify slipping hazards and, potentially, to assess intervention effectiveness.