Background Modern treatment strategies are highly successful in reducing disease activity in rheumatoid arthritis (RA). However, changes in clinical measures of disease activity may not always correspond with a patient’s own opinions of improvement.
Objectives To identify subjective predictors of self-reported health changes in patients with a good clinical response after one year of treatment in a tight control study.
Methods Data from newly diagnosed patients of the Dutch Rheumatoid Arthritis Monitoring (DREAM) remission induction cohort who completed baseline and 12 months assessments was used for this study. Patients who achieved a good DAS28 response at 12 months were selected for analysis1. Subjective change in health was assessed with the SF-36 health transition question (Compared to one year ago, how would you rate your health in general now?). Scores were dichotomized (improved vs not improved) for analysis. Binary logistic regression analysis was performed to identify predictors of patient reported health changes. Twelve month changes in DAS28 scores was added as predictor in the first step; changes in scores on SF-36 subscales were added in a second step. The general health scale of the SF-36 was excluded. Cohen’s standardized effect size (e.s.) statistic (d) was calculated for 12 month change scores of significant predictors and compared between improvers and non-improvers
Results A good DAS28 response after 12 months of treatment was achieved by 162 (57%) out of 282 patients. Of these, 40 (24.7%) did not consider their health to have improved since starting treatment (non-improvers). Baseline SF-36 subscale scores did not significantly differ between improvers and non-improvers. Twelve month change scores in bodily pain (OR = 1.03, p = 0.04) and vitality (OR = 1.03, p = 0.04) were significant multivariate predictors of self-reported health improvement. About 19% of the variance in self-reported health changes was explained by the final model (Nagelkerke’s R2 = 0.19), whereas the model containing only DAS28 change scores explained about 6% of variance (Nagelkerke’s R2 = 0.06). Mean (SD) bodily pain scores improved from 38.9 (± 18.6) to 74.7 (±19.8) over 12 months for improvers (e.s.= 1.87) and from 41.8 (±19.8) to 62.9 (±19.6) for non-improvers (e.s.= 1.06). Mean (SD) vitality scores improved from 52.8 (±19.8) to 66.7 (±16.8) in improvers (e.s. = 0.71) and from 53.12 (±18.9) to 56.56 (±18.9) for non-improvers (e.s. = 0.17).
Conclusions The majority of patients with a good DAS28 response after one year of tight control treatment also considered their health to have improved. However, a substantial minority did not consider their health to have improved, despite significant clinical improvements in disease activity. These results suggest that clinical improvements do not necessarily equate to improved subjective health. One possible explanation is that pain and fatigue are patient reported outcomes that may not be adequately represented in current clinical outcome measures in RA research.
Fransen J, van Riel PL. The Disease Activity Score and the EULAR response criteria. Clin Exp Rheumatol 2005;23(5 Suppl 39):S93-9.
Disclosure of Interest None Declared