Perceived exertion at work in women with fibromyalgia: explanatory factors and comparison with healthy women.

OBJECTIVE To investigate perceived exertion at work in women with fibromyalgia. DESIGN A controlled cross-sectional multi-centre study. SUBJECTS AND METHODS Seventy-three women with fibromyalgia and 73 healthy women matched by occupation and physical workload were compared in terms of perceived exertion at work (0-14), muscle strength, 6-min walk test, symptoms rated by Fibromyalgia Impact Questionnaire (FIQ), work status (25-100%), fear avoidance work beliefs (0-42), physical activity at work (7-21) and physical workload (1-5). Spearman's correlation coefficient and linear regression analysis were conducted. RESULTS Perceived exertion at work was significantly higher in the fibromyalgia group than in the reference group (p = 0.002), while physical activity at work did not differ between the groups. Physical capacity was lower and symptom severity higher in fibromyalgia compared with references (p < 0.05). In fibromyalgia, perceived exertion at work showed moderate correlation with physical activity at work, physical workload and fear avoidance work beliefs (rs = 0.53-0.65, p < 0.001) and a fair correlation with anxiety (rs = 0.26, p = 0.027). Regression analysis indicated that the physical activity at work and fear avoidance work beliefs explained 50% of the perceived exertion at work. CONCLUSION Women with fibromyalgia perceive an elevated exertion at work, which is associated with physical work-related factors and factors related to fear and anxiety.