Background There is growing interest in the use of patient reported outcomes in the assessment of rheumatoid arthritis (RA), along with standard clinical and physician assessments. Patients with RA are generally more sedentary than their healthy counterparts. It is not clear, however, whether this sedentary behaviour is related to their disease activity, or whether physical activity levels would improve in response to improved disease activity.
Objectives This study aimed to assess changes in disease activity, as well as changes in objectively measured physical activity levels in response to commencement of drug therapy in drug-naïve patients with RA.
Methods Eighteen RA patients completed this study as did eighteen age, sex and body mass index matched healthy control participants. At baseline, and again after three months, Actical accelerometers were fitted on the dominant hip of each participant for two weeks; and RA patients completed disease activity and functionality questionnaires.
Results After three months of drug therapy, patients had significant improvements in disease activity as assessed by the clinical disease activity index (p<0.001) and functional ability as assessed by the health assessment questionnaire (p<0.001). In parallel with these changes, the average activity counts in sedentary thresholds decreased after three months in the RA patients (p=0.010), while average activity counts within higher intensity thresholds increased. At baseline, RA patients showed diurnal differences in physical activity to healthy controls, being less physically active than control participants in the morning (p=0.048), and in the late afternoon (p=0.016), yet these diurnal patterns were no longer different after the DMARD intervention. A multiple regression showed that the change in the level of moderate activity between baseline and follow up was most highly associated with a change in C-reactive protein (β=-0.922, p=0.026). The decreases in sedentary activity and increases in moderate activity were most strongly associated with decreased morning stiffness of the joints (β=0.694, p=0.035 and β=-0.927, p=0.024 respectively).
Conclusions In conclusion, DMARD therapy significantly improved disease activity in patients with RA, and these improvements were parallel by improvements in physical activity. Actical data were also significantly correlated with multiple, well-validated disease activity measures showing the validity of the Actical as an objective outcome measure of RA.
Disclosure of Interest None Declared