Use of corticosteroids in patients with rheumatoid arthritis treated with infliximab: treatment implications based on a real-world Canadian population

OBJECTIVE: To describe the rate of concomitant oral corticosteroid use at antitumour necrosis factor (TNF) initiation and at disease remission, and to assess its effect on incidence of infection and sustainability of remission among patients with rheumatoid arthritis (RA) treated with infliximab in Canadian routine care. METHODS: Biological naïve patients with RA followed in the Biologic Treatment Registry Across Canada (BioTRAC) were included. The time-dependent association between corticosteroid dose (no use, ≤5 mg/day, >5 mg/day) and the incidence of first infection, while considering possible confounders, remission sustainability and the incidence of subsequent infections were assessed with Cox regression. RESULTS: 838 patients were included; mean (SD) baseline age and disease duration were 55.6 (13.5) and 10.5 (9.8) years, respectively. After a mean (SD) of 51.3 (43.6) months, the total incidence of adverse events (AEs) and infections were 110.2 and 19.6 per 100 person-years (PY), respectively. In multivariate analysis, the HR (95% CI) for acquiring an infection was 2.48 (1.24 to 4.98) with >5 mg/day of corticosteroids versus no corticosteroids. Similarly, ≤5 mg/day of corticosteroids was associated with increased hazard for infection (2.12 (0.97 to 4.66)). Despite DAS28 (disease activity score 28) or Clinical Disease Activity Index (CDAI) remission, corticosteroids were continued in 16.4% and 16.7% of cases, respectively. Continued corticosteroid treatment was not associated with sustainability of remission (HRDAS28 (95% CI) 1.40 (0.95 to 2.06); HRCDAI 1.19 (0.75 to 1.88)), however, it had a significant impact on development of infection (HRDAS28 (95% CI) 1.78 (1.00 to 3.19); HRCDAI 2.38 (1.14 to 4.99)). CONCLUSIONS: Oral corticosteroid treatment was associated with increased risk of development of infection without impacting sustainability of remission. These results support the notion that corticosteroids should be used concomitantly with anti-TNF for the shortest period possible to achieve remission, and then tapered. TRIAL REGISTRATION NUMBER: NCT00741793.