Real Life Evaluation of Rheumatoid Arthritis in Canadians Taking HUMIRA

The DAS28 is a validated index of rheumatoid arthritis disease activity. Twenty-eight tender joint counts, 28 swollen joint counts, erythrocyte sedimentation rate (ESR), and the Subject's Global Assessment of Disease Activity (subject rates disease activity using a likert scale from 0 [low activity] to 10 [high activity]) are included in the DAS28 score. Scores on the DAS28 range from 0 to 10. A DAS28 score >5.1 indicates high disease activity, a DAS28 score <3.2 indicates low disease activity, and a DAS28 score <2.6 indicates clinical remission.

Physical function was evaluated using the Health Assessment Questionnaire - Disability Index (HAQ-DI), a participant-reported questionnaire specific for rheumatoid arthritis. It consists of 20 questions referring to eight domains: dressing/grooming, arising, eating, walking, hygiene, reach, grip, and daily activities. Participants assessed their ability to do each task over the past week using the following response categories: without any difficulty (0); with some difficulty (1); with much difficulty (2); and unable to do (3). Scores on each task were summed and averaged to provide an overall score ranging from 0 to 3, where zero represents no disability and three very severe, high-dependency disability. Negative mean changes from baseline in the disability index of the HAQ-DI indicated improvement.

The RADAI is a questionnaire for participants used for measuring disease activity. The index consists of 6 questions. The items ask the participants about (1) global disease activity in the last 6 months, (2) disease activity in terms of current swollen and tender joints, (3) arthritis pain, (4) the current status of health, (5) duration of morning stiffness and (6) tender joints to be rated in a joint list. The joint list asks about pain in the left and right shoulders, elbows, wrists, fingers, hips, knees, ankles and toes. The first 3 items are all rated on a numeric rating scale from 0 to 10, where higher scores indicate more disease activity. The RADAI total score is the sum of individual items divided by 5 (range 0-10), with a higher score signifying more disease activity.