To evaluate the 18-month postintervention efficacy following a 4-month individually tailored behavioral intervention on daily sitting time in patients with rheumatoid arthritis (RA).
In an observer-blinded randomized trial, 150 RA patients were included. During 4 months, the intervention group (n = 75) received 3 motivational counseling sessions and tailored text messages aimed at increasing light-intensity physical activity through reduction of sedentary behavior. The control group (n = 75) maintained their usual lifestyle. The primary outcome was change from baseline to 18 months postintervention in objectively measured daily sitting time (using ActivPAL). Secondary outcomes included changes in clinical patient-reported outcomes and cardiometabolic biomarkers. A mixed-effect repeated measures analysis of covariance model in the intent-to-treat population was applied.
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 hours/day, whereas it increased by 1.32 hours/day in the control group, a between-group difference of -2.43 hours/day (95% confidence interval [95% CI] -2.99, -1.86; P < 0.0001) favoring the intervention group. For most secondary outcomes, between-group differences favored the intervention: visual analog scale (VAS) pain -15.51 mm (95% CI -23.42, -7.60), VAS fatigue -12.30 mm (95% CI -20.71, -3.88), physical function -0.39 Health Assessment Questionnaire units (95% CI -0.53, -0.26), total cholesterol -0.86 mmoles/liter (95% CI -1.03, -0.68), triglycerides -0.26 mmoles/liter (95% CI -0.43, -0.09), and average glucose -1.15 mmoles/liter (95% CI -1.39, -0.91).
The 4-month postintervention results showed that patients in the intervention reduced their daily sitting time and improved patient-reported outcomes and total cholesterol levels compared to the control group. 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.