Differences between risk situations identified using a self-reported questionnaire and an observational method

BACKGROUND: This study investigates work-related musculoskeletal disorders risk estimation by frequently as used as ergonomic methods in the field. OBJECTIVE: To identify the difference in risk estimation by an in-house observational method and a self-reported questionnaire, and to evaluate the complementary aspects of these methods. METHODS: A sample of 15 operators who worked on the assembly workstations was selected from a truck manufacturing plant. The risk assessment of these workstations (28 scenarios) was performed by the observational method and the selfreported questionnaire. The agreement between both methods to identify risk situations was measured with the weighted Kappa coefficient. RESULTS: The observational method and the self-reported questionnaire deployed on the same activity estimated different risk situations. CONCLUSIONS: This analysis does not reveal that one tool is more powerful than the other one, but shows the probability of different risk estimation. The complementary effect of each method might be considered for further investigation concerning musculoskeletal risk factors.