OBJECTIVE: To evaluate the 18-month post-intervention efficacy following a four-month individually tailored, behavioral intervention on daily sitting time in patients with rheumatoid arthritis (RA). The four-month post-intervention results showed that patients in the intervention reduced their daily sitting time, improved patient-reported outcomes and total cholesterol levels compared to the control group.

METHODS: In an observer-blinded randomized trial, 150 RA patients were included. During four months, the intervention group (n=75) received three motivational counselling sessions and tailored text messages aimed at increasing light-intensity physical activity through reduction of sedentary behavior. The control group (n=75) maintained usual lifestyle. Primary outcome was change from baseline to 18 months post intervention in objectively measured daily sitting time (ActivPAL). Secondary outcomes included changes in clinical patient-reported outcomes and cardio-metabolic biomarkers. A mixed effect repeated measures ANCOVA model in the intention-to-treat population was applied.

RESULTS: At 22-months follow-up from baseline, 12 participants were lost to follow-up. Compared to baseline, sitting time in the intervention group decreased 1.10 h/day, whereas it increased by 1.32 h/day in the control group; between-group difference of -2.43 h/day (95%CI: -2.99;-1.86; p<0.0001) favoring the intervention group. For most secondary outcomes between-group differences favored the intervention: VAS-pain: -15.51 mm (-23.42;-7.60), VAS-fatigue: -12.30 mm (-20.71;-3.88), physical function: -0.39 HAQ-units (-0.53;-0.26), total cholesterol: -0.86 (-1.03;-0.68), triglyceride: -0.26 (-0.43;-0.09) and average glucose: -1.15 (-1.39;-0.91) mmol/l.

CONCLUSION: Eighteen months after intervention, patients in the intervention group were still significantly less sedentary than controls. Findings suggest that a behavioral approach is beneficial for promoting long-term physical activity and health in patients with RA.