Relative Impact of Pain and Fatigue on Work Productivity in Patients with Rheumatoid Arthritis from the RA-BEAM Baricitinib Trial

To explore the relationship of pain and fatigue with daily activity and work productivity in rheumatoid arthritis (RA) patients from the baricitinib clinical trial, RA-BEAM. In RA-BEAM, a double-blind phase 3 study, patients were randomized 3:3:2 to placebo (n= 488), baricitinib 4 mg once daily (n= 487), or adalimumab 40 mg biweekly (n= 330) with background methotrexate. The Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) measured fatigue and the pain visual analog scale (0–100 mm) assessed pain. Work Productivity and Activity Impairment Questionnaire-RA measured daily activity and work productivity. At weeks 12 and 24, pain was assessed using pain reduction (< 30%, 30% to < 50%, ≥ 50%) and overall pain score; clinically relevant FACIT-F changes were assessed by values < 3.56 and ≥ 3.56 and the FACIT-F normative value score (< 40.1, ≥ 40.1). Pairwise comparisons between pain/fatigue reduction groups were assessed using ANCOVA with pooled data on daily activity and work productivity. A mediator analysis with pain, fatigue, and disease activity measured their contribution to daily activity and work productivity. Data were pooled from all patients for most analyses, and baricitinib-treated patients were assessed as a sensitivity analysis. Reductions in pain (≥ 50%) and fatigue (≥ 3.56) had significant (p ≤ 0.001) effects on daily activity and work productivity improvement at weeks 12 and 24. Reductions in pain, fatigue, and disease activity accounted for most of the improvements in daily activity and work productivity. At the lowest levels of remaining pain (≤ 10 mm) at weeks 12 and 24, however, fatigue did not appear to impact work productivity. Similar trends were observed with baricitinib-treated patients. Reductions in pain and fatigue were associated with improved daily activity and work productivity for all RA patients and for baricitinib-treated patients in RA-BEAM. ClinicalTrials.gov identifier, NCT01710358. Incyte Corporation and Eli Lilly and Company.