Background/Purpose: The introduction of TNF inhibitors has improved the treatment of RA, but at a substantial cost. The randomized Swefot trial compared the addition of infliximab vs conventional disease-modifying anti-rheumatic drugs in patients with early RA who had failed initial MTX monotherapy. From the Swefot trial we previously reported superior 2-year radiographic outcomes in the infliximab group, while disease-activity, quality of life and work loss improved similarly. Here we report work loss over 7 years after randomization.

Methods: In this multicenter, two-arm, parallel, randomized, active-controlled, open label trial RA patients with <1y symptom duration were recruited from 15 rheumatology clinics in Sweden between October 2002 and December 2005. After 3-4 months of MTX monotherapy, patients not achieving low disease-activity were randomized to addition of biologic treatment with infliximab or further conventional treatment with sulfasalazine+hydroxychloroquine. Register-based follow-up continued despite protocol breach, and treatment was thereafter decided by the responsible rheumatologist.

The main outcome measure in this study was yearly sick leave and disability pension days at 7 years after randomization, retrieved from the nationwide Swedish Social Insurance Office register. The analysis were by intention to treat, including all working age patients (<65y), and adjusted for work loss 1 year before randomization. Patients were followed for a maximum of 7 years and were excluded from the yearly average calculations if they (in the current year) had emigrated, died, or turned 65y.

Results: Of 210 patients in working age, 109 were randomized to infliximab (mean age=48.4y, [median=50.6y]; n women=80 [73%]) and 101 to conventional treatment (48.7y, [52.9y]; 78 [77%]). Seven patients in the infliximab and 4 in the conventional treatment group never received the study drug. The year before randomization the mean number of work days lost per year was 127 (median 112) in the infliximab arm and 118 (median 105) in the conventional treatment group (mean difference, 9; 95%CI, -22 to 39; Figure). Compared to the year before randomization, the mean changes at 7 years were -25 days in the infliximab and -26 days in the conventional treatment group (adjusted mean difference, 11; 95% CI, -24 to 46).

The cumulative work loss days over 7 years was 846 in the infliximab group and 701 in the conventional treatment group (adjusted mean difference, 105; 95% CI, -61 to 273).

Conclusion: The radiological superiority at 2 years of infliximab+MTX compared to conventional combination therapy did not translate into better long-term work loss outcomes in patients with early RA who had had an insufficient response to MTX.

Figure Mean work loss days per year in the infliximab+MTX and the conventional treatment group in relation to randomization, as well as in general population comparators.