Background High disease activity has been shown to be associated with increased risk of infection in patients with rheumatoid arthritis (RA).1 The potential benefit of lower disease activity on the risk of serious infection has not been examined.
Objectives This study was conducted to assess the impact of sustained remission on infection risk.
Methods We identified patients in the Corrona registry with at least two Clinical Disease Activity Index (CDAI) measures, at least 1 follow-visit, and met the criteria based on CDAI for sustained remission or sustained low disease activity (two incident consecutive visits in remission [CDAI ≤2.8] or LDA [CDAI between 2.8 and 10] and following the second visit (index visit) had an average disease activity in remission or LDA over follow-up using the area under the curve method based on the trapezoidal rule. Patients were followed until the earliest of: first serious infection (infection requiring either hospitalization or treatment with IV antibiotics) or last follow-up visit. Covariates identified at the index date included demographic and clinical characteristics. The incidence rates (IR) per 100 patient-years of serious infections in patients in sustained remission vs sustained LDA were calculated and crude incidence rate ratios (IRRs) calculated.
Results There were a total of 3355 RA patients in the sustained remission group and 3912 in the sustained LDA group. The majority of patients were female (75%) with mean age of 60 years, with an average disease duration of RA of 9.9 years for the sustained remission patients and 12.1 years for the sustained LDA patients (P<0.001). During follow-up, the sustained remission and sustained LDA groups reported 115 and 260 serious infections, respectively. Incidence rates between the two disease activity groups differed significantly, with the sustained LDA group having a nearly twofold (crude IRR=1.8 [1.45, 2.24]) higher rate of infections (IR=2.01 [1.78, 2.27]) than the sustained remission group (IR=1.12 [0.93, 1.34]).
Conclusions Patients in sustained remission have a lower risk of serious infections compared to those in sustained LDA. These findings may help motivate those who only attain LDA to strive to reach remission if possible.
Au K, Reed GW, Curtis JR, Kremer JM, Greenberg JD, Strand V, Furst DE. High disease activity is associated with an increased risk of infection in patients with rheumatoid arthritis. Ann Rheum Dis 2011 May;70(5):785–791.
Acknowledgement This study is sponsored by Corrona, LLC. The Corrona RA registry has been supported through contracted subscriptions in the last two years by AbbVie, Amgen, BMS, Crescendo, Genentech, Horizon Pharma USA, Janssen, Eli Lilly, Novartis, Pfizer, and UCB.
Disclosure of Interest J. Curtis Grant/research support from: Roche/Genentech, UCB, Janssen, Corrona, Amgen, Pfizer, BMS, Crescendo, Abb Vie, Consultant for: Roche/Genentech, UCB, Janssen, Corrona, Amgen, Pfizer, BMS, Crescendo, Abb Vie, M. Liu Employee of: Corrona, LLC, S. Rebello Employee of: Corrona, LLC, M. Trivedi Shareholder of: Amgen, Inc., Employee of: Amgen, Inc., T. Lesperance Shareholder of: Amgen, Inc., Employee of: Amgen, Inc., Y. Li: None declared, N. Accortt Shareholder of: Amgen, Inc., Employee of: Amgen, Inc.