OBJECTIVE: To assess the association between the initiation of anti-tumor necrosis factor alpha (anti-TNFalpha) therapy and the risk of serious bacterial infections in routine care. METHODS: This was a cohort study of patients with rheumatoid arthritis (RA) in whom specific disease-modifying antirheumatic drugs (DMARDs) were initiated. Patients were Medicare beneficiaries ages 65 years and older (mean age 76.5 years) who were concurrently enrolled in the Pharmaceutical Assistance Contract for the Elderly provided by the state of Pennsylvania. A total of 15,597 RA patients in whom a DMARD was initiated between January 1, 1995 and December 31, 2003 were identified using linked data on all prescription drug dispensings, physician services, and hospitalizations. Initiation of anti-TNFalpha therapy, cytotoxic agents other than methotrexate (MTX), noncytotoxic agents, and glucocorticoids was compared with initiation of MTX. The main outcome measure was serious bacterial infections that required hospitalization. RESULTS: The incidence of serious bacterial infections was, on average, 2.2 per 100 patient-years in this population (95% confidence interval [95% CI] 2.0-2.4). Glucocorticoid use doubled the rate of serious bacterial infections as compared with MTX use, independent of previous DMARD use (rate ratio [RR] 2.1 [95% CI 1.5-3.1]), with a clear dose-response relationship for dosages >5 mg/day (for /=20 mg/day, RR 5.48 [P for trend < 0.0001]). Adjusted models showed no increase in the rate of serious infections among initiators of anti-TNFalpha therapy (RR 1.0 [95% CI 0.6-1.7]) or other DMARDs as compared with initiators of MTX. CONCLUSION: In a large cohort of patients with RA, we found no increase in serious bacterial infections among users of anti-TNFalpha therapy compared with users of MTX. Glucocorticoid use was associated with a dose-dependent increase in such infections. [ABSTRACT FROM AUTHOR]
Copyright of Arthritis & Rheumatism is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
