LAUSR

BACKGROUND Retrospective researches partly characterize the link between antibiotic use and rheumatoid arthritis (RA) development. This prospective cohort study may help to reassess the association. RESEARCH DESIGN AND METHODS We included 133 125 participants from the Nurses' Health Study (NHS) and NHS II databases. Three groups were established: non-use, short-term use (1-14 days), and middle- to long-term use (≥15 days) to explore the link. Cox regression model was chosen to evaluate the hazard ratios (HRs) for RA. RESULTS Short-term antibiotic use was not associated with subsequent risk of RA (adjusted HR=0.88, 95% Confidence Interval [CI] 0.38-1.38) compared to the no antibiotic use group in the multivariable adjusted model. The age-stratified model showed no sufficient evidence of increased risk in participants with middle- to long-term antibiotic use (HR=1.32, 95% CI 0.89-1.98). The effect further attenuated to null after controlling for confounding factors (adjusted HR=1.06, 95% CI 0.42-1.71). CONCLUSIONS We found no evidence of an association between antibiotic use and RA risk. Our findings may reduce potential concerns about increased RA risk among antibiotic users.