Do oral contraceptives prevent rheumatoid arthritis?

Area of Science:

• Epidemiology
• Rheumatology
• Women's Health

Background:

• Previous studies suggested oral contraceptives (OCs) reduced rheumatoid arthritis (RA) risk.
• A Mayo Clinic study failed to confirm these findings, facing criticism for methodological limitations.

Purpose of the Study:

• To resolve the controversy regarding OCs and RA risk.
• To conduct a population-based case-control study with improved methodology.

Main Methods:

• A population-based case-control study design.
• Utilized expanded Mayo Clinic data and Planned Parenthood records for comprehensive OC use ascertainment.
• Included 182 cases and 182 matched controls, with 2.2 times more eligible cases than prior studies.

Main Results:

• The relative risk (RR) of RA for any prior OC use was 1.1 (95% CI 0.7–1.7).
• The RR for current OC use was 1.3 (95% CI 0.7–2.4).
• No statistically significant protective effect of OCs on RA risk was observed.

Conclusions:

• The study found no evidence that oral contraceptive use reduces the risk of rheumatoid arthritis.
• Findings were consistent across different age groups, disease severity, and outcome definitions.