No association between recent antibiotic use and risk of rheumatoid arthritis: results from two prospective cohort studies

Background: Retrospective research partly characterizes the link between antibiotic use and rheumatoid arthritis (RA) development. This prospective cohort study may help 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: nonuse, 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 the 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.