Health-related quality of life in fibromyalgia patients: a comparison with rheumatoid arthritis patients and the general population using the SF-36 health survey

To compare health-related quality of life (HRQL) in fibromyalgia (FM) patients with that of patients with rheumatoid arthritis (RA) and the general population, and investigate if the factors are associated with the greater impact of FM. This cross-sectional study involved 380 patients with FM, 693 patients with RA and 1579 healthy controls. HRQL was evaluated using the Medical Outcome Study Short-Form 36 (SF-36), and the measures included disease-related characteristics, demographic variables and comorbidities. S-scores were calculated for comparisons with the norm, and multivariate analyses were used to assess the relationships between HRQL and clinical and demographic variables. In comparison with the general population, the FM patients showed significant impairment in relation to all of the eight scales of the SF-36 (p