To explore the interrelationships between the psychosocial and illness factors that determine the disease status of patients with rheumatoid arthritis (RA) and to identify how each factor is associated with quality of life (QOL).
The study group comprised 120 RA outpatients who completed a series of health examinations and questionnaires. Disease severity, functional disability, counts of swollen and/or tender joints, duration of RA, frequency of arthritis surgery, and C-reactive protein level were assessed by rheumatologists. Self-report inventories completed by the patients were used to assess perceived degree of pain, fatigue (visual analogue scales), depression (Beck Depression Inventory-II), anxiety (Hospital Anxiety and Depression Scale), and social support (Social Support Questionnaire). Mental and physical components of health-related QOL were evaluated using the Short-Form 36 Health Survey.
After z-transformation of the data, a principal axis factor analysis was conducted. A four-factor structure was identified in which the components reflected psychosocial factors, disease activity, current symptoms, and physical functional status, respectively. There was no significant association between psychosocial factors and disease activity, while the other components were moderately correlated with each other. Multiple regression analysis revealed that physical QOL was determined by current symptoms and physical functions. Mental QOL was determined by psychosocial factors, current symptoms, and physical functions.
Disease activity was independent from psychosocial factors and failed to reflect the perceived physical and mental QOL of RA patients. Clinicians should therefore evaluate psychosocial factors, as well as subjective disease status, to improve the QOL of patients with RA.