To analyze longitudinal data over 5 years for changes in Health Assessment Questionnaire (HAQ) scores in patients with rheumatoid arthritis (RA) and age- and sex-matched controls from the general population.
In 2000 and 2005, identical self-report questionnaires were mailed to a cohort of patients with RA and control cohort from the community. The questionnaire included the HAQ, which was used to assess functional status. Changes in HAQ scores over 5 years were analyzed.
In 2000, 73% of 1,495 patients with RA and 77% of 2,000 general population controls responded to the questionnaire. In 2005, 84% of 2,022 patients with RA and 77% of 1,817 controls responded. A total of 863 patients with RA and 1,176 community controls responded in both 2000 and 2005 and were included in the analyses. Mean baseline HAQ scores were significantly higher in patients with RA than in controls (0.71 versus 0.17; P < 0.001). Over 5 years, the HAQ scores increased by 0.01 units per year in both the RA cohort and the community population; in both cohorts, the net change was primarily attributable to individuals over age 70 years. Changes in HAQ scores were similar in patients and controls who had low HAQ scores at baseline. Female patients with baseline HAQ scores of >or=0.5 had less potential for improvement than did controls. Among subjects in both groups who had HAQ scores >2, death was a common outcome over the next 5 years.
Currently, progression of functional disability among patients with RA and among persons in the general population is largely explained by the aging process. Our results showing stable function scores over 5 years in most patients with RA who are younger than age 70 years provide further evidence of improved status of RA patients today compared with the major declines observed in previous decades.