Abstract
BackgroundThere have been few community-based epidemiological studies in which the prevalence of exogenous hormone use, including the use of oral contraceptives (OCs) and hormone replacement therapy (HRT), has been accurately assessed in Japan.MethodsWe have been conducting repeated surveys of participants in the Japan Nurses’ Health Study (JNHS), as a nationwide prospective cohort study, since 2001. We determined the prevalence of exogenous hormone use at baseline and during a 10-year follow-up period. A total of 15,019 female nurses participated in the JNHS follow-up cohort. We determined the prevalence of OC use in 14,839 women <60 years of age at baseline and the prevalence of HRT use in 7,915 women, excluding premenopausal women, at the last time they answered a questionnaire. The duration of HRT use was estimated using the Kaplan-Meier method.ResultsSix percent of the participants used OCs. The proportion of HRT users who stopped HRT before the baseline survey, the proportion of women using HRT during the follow-up period, and the proportion of all of the participants who had used HRT were 3.2%, 10.6%, and 13.8%, respectively. The median duration of HRT use was 2 years.ConclusionsThe lifetime prevalences of exogenous hormone use during this prospective study conducted in Japanese nurses were 6.0% for OCs and 13.8% for HRT. The information obtained in this study will be useful for clarification of the association between exogenous estrogen exposure and estrogen-related diseases as future research.
Highlights
In women of reproductive age, oral contraceptives (OCs) are the most effective and widely used forms of contraception
In the United States, it was reported that the annual proportion of women aged 50–74 years who were on hormone replacement therapy (HRT) declined from 42% in 2001 to 28% in 2003.5 The proportion of women undergoing HRT decreased in 17 European countries.[6]
The prevalences of OC use were 2.8% in women who were born in the 1950s, 7.8% in women who were born in the 1960s, 10.6% in women who were born in the 1970s, and 20.8% in women who were born after the 1980s
Summary
In women of reproductive age, oral contraceptives (OCs) are the most effective and widely used forms of contraception. In the United States, more than 80% of sexually active women aged 15–44 years have reported using OCs.[1] A survey conducted by the Japan Family Planning Association showed that the prevalence of OC use in Japan in 2004 was 3.0%.2. There have been few epidemiological studies in which the extent of OC use was assessed in a longitudinal study in Japan. There have been few community-based epidemiological studies in which the prevalence of exogenous hormone use, including the use of oral contraceptives (OCs) and hormone replacement therapy (HRT), has been accurately assessed in Japan
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
