Validity of a Questionnaire for the Assessment of Work-related Musculoskeletal Symptoms and Physical Demands

Abstract

Background: Participatory ergonomics interventions are frequently based on the use of self-answered questionnaires intended to gathering information on work-related musculoskeletal symptoms and physical demands reported by workers. The aim of this study is to assess the validity of a questionnaire designed to be applied in these programs. Methods: Thirty five volunteer workers from ten different companies located in Valencia and Alicante (Spain) agreed to participate. Field work was developed in 2009. Three complementary approaches were applied: reproducibility in two administrations of the questionnaire; comparing data in the questionnaire with data from direct observation of workplaces; and comparing data in the questionnaire with data from routine reports of health surveillance and risk assessment in participating companies. Results: Agreement indices (weighted kappa, wK) in reproducibility analyses for musculoskeletal symptoms in the different parts of the body (thighs being the only exception) were between 0.32 (95%CI 0.05-0.59) and 0.70 (95%CI 0.41-0.99). In general, the same analyses for exposure to the different ergonomic risks yielded lower agreement indices; e.g., wK for neck positions between 0.36 (backwards, 95%CI 0.11-0.61) and 0.55 (forwards, 95%CI 0.30-0.80). In the analyses comparing with data from workplace observation, agreement indices were lower. Most items in the questionnaire show acceptable levels of agreement in reproducibility analyses, but lower indices when comparing with observation Conclusions: Most of musculoskeletal symptoms and physical demands self-reported by the workers in the questionnaire were not included in the companies' routine health surveillance and risk assessment reports.The questionnaire is a more sensitive tool than routine health surveillance and risk assessments practices in order to identify perceived problems by workers.