556. Hospitalization for Infection in a National Cohort of Veterans with Rheumatoid Arthritis (RA)
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: Disease modifying anti-rheumatic drugs (DMARDs) and prednisone are the mainstay of treatment for RA. The impact of these medications on hospitalization for infection is unclear.
Methods: The study period was October 1st, 1998 to September 30th, 2006. The study sample included all patients enrolled in Department of Veterans’ Affairs healthcare who, during the study period, 1) had an ICD-9 diagnosis of RA, 2) began taking a DMARD, and 3) had at least two clinical encounters. Demographics, ICD-9 codes, healthcare utilization and medication data were obtained from the VA's national administrative and pharmacy databases. The National Hospital Discharge Survey (NHDS) was used to create a composite variable composed of all ICD-9 codes for infection that caused at least 10,000 hospitalizations in 2005. A hospitalization was considered to be “for infection” if the primary ICD-9 code for that hospitalization was part of this composite variable. Risk of outcomes was described using hazard ratios and 95% confidence intervals. Time-to-event analysis was performed using Cox proportional hazards regression.
Results: A total of 20,814 subjects met inclusion criteria, and 1,465 of these (7.0%) were hospitalized at least once for infection. The most common hospitalized infections were pneumonia, bronchitis, and cellulitis. Age and several comorbid medical conditions predicted hospitalization for infection. Prednisone (HR 2.06, 95% CI = 1.85-2.29) and TNF inhibitor (HR 1.32, 95% CI = 1.12 - 1.56) use predicted hospitalization for infection. Use of DMARDs other than TNF inhibitors was not predictive of hospitalization for infection. In all treatment groups, hospitalization for infection was most frequent in the first 12 months of therapy.
Conclusion: Prednisone and TNF inhibitor use predicted hospitalization for infection, while the use of other DMARDs did not.
Liron Caplan, MD1, Seth A. Eisen, MD, MSc2, Michael Lane, MD, MSc3, Jay McDonald, MD3, Prabha Ranganathan, MD3, Angelique Zeringue, MS3 and  M. A. Lane, None..
J. R. McDonald, None..
A. L. Zeringue, None..
L. Caplan, None..
P. Ranganathan, None..
S. A. Eisen, None., (1)Denver VA Medical Center, Denver, CO, (2)VA HSR&D, Washington, DC, (3)Washington University School of Medicine, St. Louis, MO