Is reduced health-related quality of life a primary manifestation of fibromyalgia? A comparative study with Rheumatoid arthritis.

The fact that group differences in HRQoL remained highly significant after statistically controlling of group differences in clinical symptom severity, and that associations between clinical symptoms and HRQoL disappear when the type of diagnosis was considered in the regression analysis, suggest that impairment of HRQoL could be considered a primary feature of FMS.