Which aspects of health differ between working and nonworking women with fibromyalgia? A cross-sectional study of work status and health

Background: Women with fibromyalgia (FM) describe great difficulties in managing work. Reported work ability in women with FM varies from 34 to 77 percent in studies from different countries. Many factors are suggested to affect the ability to work in women with FM, including pain, fatigue, impaired physical capacity and activity limitations. However, it is difficult to define to which extent symptom severity can be compatible with work. The aim of this study was to investigate which aspects of health differ between working women with FM and nonworking women with FM. Methods: A cross-sectional study of 129 women of working age with FM which included clinical assessment, structured interviews, questionnaires and performance-based tests. The women were categorized as working or nonworking. Aspects of health are presented according to the International Classification of Functioning, Disability and Health (ICF). Results: Working women with FM presented better health than nonworking women with FM in ratings of body function (FIQ pain p < 0.001, FIQ fatigue p = 0.006, FIQ stiffness p = 0.009, HADS-Depression p = 0.007). Ratings of overall health status were also significantly better in working women with FM than in nonworking women with FM (FIQ total, eight-item p = 0.001 and SF-36 PCS p < 0.001). No significant differences were found between working- and nonworking women in tests of physical capacity. FIQ pain was an independent explanatory factor for work in stepwise multiple logistic regression analysis (OR 0.95, CI 0.93-0.98), p < 0.001. Conclusion: Working women with FM reported better health than nonworking women with FM in terms of pain, fatigue, stiffness, depression, disease specific health status and physical aspects of quality of life, which represent body functions and overall health status. However, they were equally impaired in tests of physical capacity. Moderate pain levels were compatible with work, while severe pain appeared to compromise work. Fatigue was better tolerated, as women scoring severe levels of fatigue worked.