Prior oral contraception and postmenopausal fracture: a Women's Health Initiative observational cohort study.
OBJECTIVE
To test for the possible association of past oral contraceptive (OC) use and incident fracture after menopause.


METHODS
A prospective cohort of 93,725 postmenopausal women.


METHODS
Forty Women's Health Initiative (WHI) clinical centers across the United States.


METHODS
Ethnically diverse 93,725 volunteer postmenopausal women, 50 to 79 years old.


METHODS
None.


METHODS
The main outcome was self-reported incident first fracture assessed prospectively by annual questionnaire.


RESULTS
The adjusted relative hazard (HR) for fracture among past OC users was 1.07 (95% CI, 1.01-1.15). Among women without any postmenopausal hormone treatment, past OC use for < or =5 years led to an HR of 1.15 (95% CI, 1.04-1.27) and for past OC use >5 years led to an HR of 1.09 (95% CI, 0.97-1.23) compared with never users.


CONCLUSIONS
This study does not support the idea that past OC use protects against later fracture.
Barad
David
D
Obstetrics and Gynecology & Women's Health, Department of Epidemiology and Social Medicine, Albert Einstein College of Medicine, Bronx, New York 10021, USA. dbarad@whi.org
Kooperberg
Charles
C
Wactawski-Wende
Jean
J
Liu
James
J
Hendrix
Susan L
SL
Watts
Nelson B
NB
D000368:Aged; D015331:Cohort Studies; D016001:Confidence Intervals; D003276:Contraceptives, Oral / Q000008:administration & dosage*; D015914:Estrogen Replacement Therapy / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000453:epidemiology* / Q000517:prevention & control*; D006620:Hip Fractures / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000187:drug effects* / Q000502:physiology; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States; D016387:Women's Health
D003276:Contraceptives, Oral