Effect of TNF antagonists on the productivity of daily work of patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a significant cause of work disability and job loss. The resulting economic burden experienced by patients has received considerable research attention. This research assesses the effect of tumor necrosis factor (TNF) antagonists (infliximab, etanercept) on the ability of RA patients living in Japan to work and participate in society. A total of 42 patients with active RA were enrolled and given biological therapy for 12 months (mo). Of these patients, 14 were employed full-time, 6 were employed part-time, and 22 were not employed. Twenty-six patients were given infliximab, and sixteen were given etanercept. The amount of domestic labor performed before the biologics served as a baseline and was assigned a value of 0%. After treatment with biologics, the productivity was evaluated using the visual analog scale (VAS; -100 to +100 mm). The administration of TNF antagonists to RA patients who exhibited an insufficient response to medical treatment significantly improved the Disease Activity Score 28 (DAS 28) after both 6 mo and 12 mo (P < 0.0001). A significant correlation was found between the improvement in their DAS 28 and improvements in their work situation (Productivity VAS) (P < 0.05). Of particular interest is the significant correlation between the values of baseline mHAQ and the percent changes of Productivity VAS that was observed after 6 mo and 12 mo (P < 0.05). Our findings indicate that medical treatment of RA with TNF antagonists improves the patients' ability to perform their jobs and housekeeping. Because loss of productivity is an important contributor to the indirect costs of RA, our findings are relevant for the pharmacoeconomic assessment of treatments.