Background Patients with rheumatoid arthritis (RA) have increased susceptibility for infections, which contributes to increased mortality.
Objectives To compare the rates of serious infections among patients diagnosed with RA in 1995-2007 to rates previously reported among patients with RA from the same geographical area who were diagnosed in 1955-1994.
Methods A population-based inception cohort of patients with RA who fulfilled 1987 ACR criteria for RA in 1995-2007 was assembled and followed through their complete medical records until death, migration, or 12/31/2008. The outcome measures included all serious infections (requiring hospitalization or IV antibiotics), which were categorized into the following types: bacteremia/septicemia, septic arthritis, osteomyelitis, pneumonia, lower respiratory tract, urosepsis/ pyelonephritis, skin/soft tissue, gastrointestinal, intra-abdominal and other. Urinary tract infections were excluded. Person-year methods were used to compare rate of infection by type for patients diagnosed in 1955-1994 vs. 1995-2007.
Results Among the 464 patients with RA diagnosed in 1995-2007 (mean age 56 years; 69% female; mean followup 5.9 years; 2,715 total person-years [py]), 54 had ≥1 serious infection (178 total serious infections). They were compared to 609 patients with RA diagnosed in 1955-1994 (mean age 58 years; 73% female; mean followup 12.7 years; 7,730 total py), of which 290 experienced ≥1 serious infection (740 total serious infections). The rate of serious infections in patients in the 1995-2007 time period (6.6 per 100 py) was less than in the 1955-1994 time period (9.6 per 100 py). The rates of each type of serious infections declined in the 1995-2007 time period compared to the 1955-1994 time period with one exception: the rate of serious gastrointestinal infections (including diverticulitis, gastroenteritis and infective colitis) increased from 0.5 per 100 py in the 1955-1994 cohort to 1.25 per 100 py in the 1995-2007 time period.
Despite the decline in rates of serious infections over time, the rate of subsequent infection following the first serious infection increased from 16.5 per 1000 py in the 1955-1994 cohort to 37.4 per 100 py in the 1995-2007 cohort.
Conclusions With the exception of gastrointestinal infections, the rate of serious infections in patients with RA has declined in recent years. However, subsequent infections are more common in recent years than previously.
Disclosure of Interest E. Matteson Grant/Research support from: Genentech Pharmaceuticals, P. Fitz-Gibbon Grant/Research support from: Genentech Pharmaceuticals, C. Crowson Grant/Research support from: Genentech Pharmaceuticals
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.