The assessment and prediction of functional disability in rheumatoid arthritis.

We assessed functional disability with the Stanford Health Assessment Questionnaire Functional Disability Index (FDI) in 1,274 patients with rheumatoid arthritis (RA) followed longitudinally for up to 12 years. The rate of functional loss increased sharply after the first clinic visit. Half of patients with RA (median survival time) will reach FDI scores of about 1 in 2 years, 2 in 6 years, and 2.5 in 10 years after the first clinic visit, levels that correspond to moderate, severe and very severe loss of functional ability. Functional outcomes may be predicted by simple demographic and clinical assessments, the best of which are self-assessed measures of global severity, pain and function.