Development and validation of a work-related risk score for upper-extremity musculoskeletal disorders in a French working population

International audience ; Objectives: The aim was to develop an easy-to-use risk score based on occupational factors and to validate its performance to identify workers either having (diagnostic setting) or developing (prognostic setting) upper-extremity musculoskeletal disorders (UEMSD).Methods: This study relied on data from the Cosali prospective cohort conducted in a French working population. Diagnostic status for six UEMSD at inclusion and at follow-up was assessed by a standardized clinical examination. Data on occupational factors were collected through a self-administered questionnaire completed before the clinical examination at inclusion. The risk score was derived from a prediction model developed on data of 2,468 workers included in 2002-2003, and the validation sample is composed of 1,051 workers included later in 2004-2005. The prognostic performance of the risk score was assessed in workers without UEMSD at baseline.Results: A total of 13% and 12% of workers had a UEMSD at inclusion in the development and validation sample. The developed risk score includes physical, organizational and psychosocial factors at work. In the validation sample, this score had acceptable performance for identifying workers having or not UEMSD at baseline (AUC: 0.60 [95% CI 0.57 to 0.63]), in particular the negative predictive value was high (89%-90%). The baseline risk score showed similar performance for predicting incident UEMSD at follow-up examination.Conclusion: This score can be useful as a first-line risk assessment tool, especially for excluding the low-risk work situations from further intervention by an ergonomist. Further validation studies are needed to determine its performance among various working populations.