Frequency of infection in patients with rheumatoid arthritis compared with controls: A population‐based study

A high frequency of infections complicating rheumatoid arthritis (RA) has been described in reports of case series. This retrospective longitudinal cohort study was undertaken to compare the frequency of infections in a population-based incidence cohort of RA patients with that in a group of individuals without RA from the same population.

RA patients included all members of an incidence cohort of Rochester, Minnesota residents ages >or=18 years who were first diagnosed as having RA between 1955 and 1994. One age- and sex-matched subject without RA was selected for each patient with RA. Study subjects were followed up by review of their entire medical record until death, migration from the area, or study end (January 1, 2000), and details of all documented infections, along with information on potential risk factors for infection, were recorded. Hazard ratios for infections were estimated using stratified Andersen-Gill proportional hazards models, with adjustment for potential confounders.