We studied clinical and health status measures in 561 patients with rheumatoid arthritis (RA). Two hundred sixty-four patients were seen within 2 years of disease onset and followed for an additional 2 years. Four other groups were each followed for 5 years, and had disease durations of 2-7, 7-12, 12-17, and 17-22 years, respectively, at the first clinic visit. Functional disability developed very early in the course of RA and continued to worsen at about an equal rate over 22 years. Anxiety, pain scores, and self-assessed severity also increased with time, but erythrocyte sedimentation rate (ESR), morning stiffness, and joint counts were unchanged. Treatment resulted in reduction in joint counts and in nonsignificant improvements in ESR, stiffness, and psychological scores. But functional loss increased in each time period in spite of treatment. Variables most effective in controlled clinical trials are not effective as longterm measures of RA outcome.