Background Patients with rheumatoid arthritis (RA) are more sedentary than the general population, which can have serious health consequences. Reducing sedentary behaviour (SB) and increasing light intensity physical activity is advocated as a potentially more achievable health promotion focus in patients with chronic diseases and mobility problems. Intervention studies have shown that behavioural approaches are effective in reducing SB in healthy populations. Whether this applies to patients with RA is yet to be determined.

Objectives To test the efficacy of a 16-week individually tailored, behavioural intervention in reducing daily sitting time, pain and fatigue and improving health-related quality of life, self-efficacy, physical function and cardio-metabolic disease risk in patients with RA.

Methods Parallel-group, observer-blinded randomised controlled trial (N=150). RA patients >18 years of age, self-reported daily sitting time >5 hours and Health Assessment Questionnaire (HAQ) score <2.5 were consecutively recruited from a rheumatology outpatient clinic. The intervention group (n=75) received three individual motivational counselling sessions with a health professional and text messages aiming at improving motivation for light intensity physical activity through reduction of SB. The control group (n=75) was encouraged to maintain usual lifestyle. Primary outcome was change from baseline in daily sitting time measured objectively by ActivPAL, analysed using ANCOVA with a factor for group and adjustment for the outcome level at baseline. Primary analyses were based on the intention-to-treat population. Secondary outcomes included patient-reported outcomes and cardio-metabolic biomarkers (blood pressure, cholesterol levels, blood glucose, body weight and waist circumference).

Results After 16 weeks, three participants were lost to follow-up. There was a mean decrease in daily sitting time of 1.61 hours (h)/day with the intervention and an increase of 0.59 h/day in the control group; between-group difference was -2.20 h/day (95%CI: -2.72 to -1.69; p<.0001) in favour of the intervention group. Most of the secondary outcomes were also in favour of the intervention; VAS-pain: -22.36 (-29.27 to -15.44); VAS-fatigue: -26.80 (-34.32 to -19.30), physical function (HAQ): -0.42, (-0.54 to -0.30) and total cholesterol: -0.37 (-0.50 to -0.24) mmol/l.

Conclusions An individually tailored, behavioural intervention effectively reduced daily sitting time by on average more than two hours in patients with RA and additionally improved patient-reported clinical outcomes and cholesterol levels. The results may be important for clinical practise and physical activity recommendations for patients with RA and can most likely be generalised to other populations with chronic disease and mobility limitations.

Disclosure of Interest None declared