Both the presence of fibromyalgia (FM) and increasing number of FM symptoms predicted worsening of functional status among individuals with rheumatoid arthritis (RA), according to a recent study. Subjects included participants in the Brigham Rheumatoid Arthritis Sequential Study enrolled in a sub-study of the effects of pain in RA. They completed questionnaires, including the Multi-Dimensional Health Assessment Questionnaire (MDHAQ) and Polysymptomatic Distress (PSD) Scale, semi-annually and underwent physical examination and laboratory tests yearly. Researchers found:

• Of the 156 included RA subjects, 16.7% had FM, while 83.3% did not.
• In a multivariable linear regression model adjusted for age, gender, race, baseline MDHAQ score, disease duration, rheumatoid factor (RF)/cyclic citrullinated peptide antibody (CCP) seropositivity, disease activity, and psychological distress, RA patients with FM had a 0.14 greater 2-year increase in MDHAQ score than RA patients without FM.
• In secondary analyses examining the association between continuous PSD Scale score and change in MDHAQ, higher PSD Scale scores were significantly associated with greater 2-year increases in MDHAQ score.