Association between disease activity measured by RAPID3 and health-related quality of life in patients with rheumatoid arthritis

Routine assessment of patient index data 3 (RAPID3) is a simple, valid and reliable tool designed to measure disease activity in patients with rheumatoid arthritis (RA). RA causes significant disability and diminishes health-related quality of life (HR-QoL). The aim of this study was to investigate how RAPID3 is related to HR-QoL in patients with RA. In this cross-sectional study performed at the tertiary outpatient clinic 68 consecutive patients (58 females, and 10 males) with established RA were enrolled. RAPID3 and EuroQoL-5D-3L (EQ-5D-3L) were used to measure disease activity and quality of life, respectively. Alongside, demographic and clinical data were obtained, as well as HAQ-DI as a measure of physical function, and Steinbrocker’s score for radiographic damage. To test the relationships among RAPID3 and study variables we used the Pearson product–moment correlation coefficient, with the significance was set at P < 0.05. Linear and forward stepwise regression was used to show how variables of interest contributed to RAPID3. The mean value of RAPID3 (standard deviation, SD) was 14.12 (± 5.21), while the median (IQR) value of EQ-5D-3L was 0.51 (0.62–0.23). There was a high significant correlation (r = − 0.73) between RAPID3 scores and EQ-5D-3L. Among the other variables of interest, the strongest correlation was found between RAPID3 and intensity of pain (r = 0.88), while the EQ-5D-3L and pain were moderately correlated (r = − 0.68). In evaluating the influence of variables of interest on RAPID3, a forward stepwise regression model was constructed to evaluate whether VAS pain, EQ-5D-3L and EQ-VAS predicted RAPID3. The given variables significantly explained approximately 81% of the variation in RAPID3. Based on the results of this study RAPID3, a simple and practical tool to assess disease activity, reflects well HR-QoL in patients with established RA.