The use of exogenous sex hormones in relation to the risk of rheumatoid arthritis (RA) was examined in a cohort of married nurses 30-55 years of age followed since 1976 in the Nurses' Health Study. Baseline information on the use of oral contraceptives, replacement estrogens, and other potential risk factors was obtained in 1976 and updated every 2 years. During 8 years of followup, 217 incident cases of polyarthritis were ascertained (115 RA and 102 undifferentiated polyarthritis). When compared with women who had never used oral contraceptives, the age-adjusted relative risk was 1.0 (95

作者：M, Hernandez-Avila；M H, Liang；W C, Willett；M J, Stampfer；G A, Colditz；B, Rosner；R W, Chang；C H, Hennekens；F E, Speizer

来源：Arthritis and rheumatism 1990 年 33卷 7期