Purpose: Musculoskeletal disorders are extremely frequent and account for an important part of the global burden of disease. Risk factors for musculoskeletal disorders include sustained occupational exposure to physically demanding jobs. The effects of sustained occupational physical exposures on knee and shoulder pain are known to persist after retirement; also, several studies have shown a socio-economic gradient in health and quality-of-life outcomes, including for musculoskeletal pain. It is thus possible that prolonged occupational exposures affect workers differently in the long-term along a socio-economic gradient. This study was conducted to investigate whether the impacts of severe shoulder/arm and knee/leg pain on the quality of life of retired workers follow a socio-economic gradient.
Methods: Data from the French GAZEL cohort study (n = 14,249) were used to compare the impacts of severe shoulder/arm and knee/leg pain separately on the SF-36, Nottingham Health Profile and limitations in activities of daily living measured in 2006 and 2007, between four groups of social position (measured in 1989). Analyses were made in 2014 with multiple linear and logistic regressions and stratified by sex.
Results: For both pain sites, in men and women, there was a strong general tendency for the impacts of severe pain to be smaller among participants in higher social positions. Most important differences were related to pain and physical limitations.
Conclusions: These results suggest inequalities in the impacts of severe joint pain by socio-economic status. The source of these inequalities is still speculative and merits the scientific attention.
Keywords: Knee pain; Quality of life; Retirement; Shoulder pain; Social inequalities.