Use of a disease risk score to compare serious infections associated with anti-TNF therapy among high versus lower risk rheumatoid arthritis patients
Arthritis Care & Research , 05/15/2012
Curtis JR et al. – The rate of serious infections for anti–TNF agents was incrementally increased by a fixed absolute difference irrespective of age, comorbidities, and other factors that contributed to infections. Older patients and those with high comorbidity burdens should be reassured that the magnitude of incremental risk with anti–TNF agents is not greater for them than for lower risk patients.Methods
- Among new non–biologic disease modifying anti–rheumatic drug (DMARD)users enrolled in Medicare/Medicaid or a large U.S. commercial health plan, the authors created and validated a person–specific infection risk score based upon age, demographics, insurance, glucocorticoid dose, and comorbidities to identify patients at high risk for hospitalized infections.
- They then applied this risk score to new users of infliximab, etanercept, and adalimumab and compared the observed one–year rate of infection to each other and to the predicted infection risk score estimated in the absence of anti–TNF exposure.
- Among 11,657 rheumatoid arthritis (RA) patients initiating anti–TNF therapy, the observed one year rate of infection was 14.2 per 100 person–years in older patients (>= 65 years) and 4.8 in younger patients (< 65 years).
- There was a relatively constant rate difference of 1–4 infections per 100 person–years associated with anti–TNF therapy across the range of the infection risk score.
- Infliximab had a significantly greater adjusted rate of infection compared to etanercept and adalimumab in both high and lower risk RA patients.