Development of a model to measure symptom status in persons living with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic illness with a constellation of symptoms. The management of which is important for quality of life. Our review of the literature indicated that there is currently no standardized approach to measuring the symptom status of persons living with RA.

The purpose of this study is to report the development and initial validation of a structure to measure symptom status in persons living with RA.

For this secondary analysis, there were 901 female patients with complete symptom checklists available from the Arthritis, Rheumatism, and Aging Medical Information System. A tentative structure using exploratory factor analysis was developed, the structure was replicated in a separate sample using confirmatory factor analysis, and then hypothesized relationships with an external criterion (functional health) was tested using structural equation modeling. The symptom checklist contains 31 symptoms. The stem question is, "Have you had any of the following symptoms during the past 6 months; if yes mark all that apply."

A two-factor structure for measuring symptom status was identified, RA Pain Symptoms and General Symptoms. Using the external criterion, we also demonstrated that the two factors were different and that the RA Pain Symptoms Factor had a stronger impact on functional health. This provides evidence of the discriminant as well as predictive validity of the RA Pain Symptoms Factor.

Effective symptom management is an important outcome for nursing practice. Because the assessment of symptoms is the first step in symptom management, the identification of a measurement structure is an essential step.