Similar prediction of mortality by the health assessment questionnaire in patients with rheumatoid arthritis and the general population

Background: The self report health assessment questionnaire (HAQ) quantifies disability in activities of daily living (ADL). In patients with rheumatoid arthritis, the HAQ predicts mortality, work disability, and hip replacement surgery. It has been widely used in rheumatology, but population based data are rare. Objective: To determine whether the HAQ predicts mortality in patients with rheumatoid arthritis (n = 1095) and community controls ( n = 1490). Methods: A mailed questionnaire including the HAQ, visual analogue scales for pain and global health, comorbidities, education level, height, weight, and smoking status was administered in June 2000. Two years later, the vital status of the subjects was ascertained from the Finnish Population Register database. Results: There were 41 deaths (10.1%) among the 404 patients with rheumatoid arthritis who had a baseline HAQ greater than or equal to 1 ( indicating at least some difficulty in most ADL), and 16 (2.3%) among 691 patients with HAQ<1 (p<0.001); in the community controls the values were 20 (13.6%) among 147 with HAQ greater than or equal to1, and 14 (1.0%) among 1343 with HAQ <1 (p<0.001). A higher HAQ score was an independent predictor of mortality in patients with rheumatoid arthritis (hazard ratio 2.73 (95% confidence interval, 1.86 to 4.02); p< 0.001) and in community controls (2.75 (1.61 to 4.70); p< 0.001). Conclusions: The HAQ predicts mortality in the community population as well as in patients with rheumatoid arthritis. People with similar levels of disability appear to have a similar likelihood of mortality over two years.