Factors associated with age of onset and type of menopause in a cohort of UK women

OBJECTIVE: We sought to describe the pattern of age at menopause and factors associated with type of menopause. STUDY DESIGN: This was a prospective cohort study of 5113 postmenopausal health survey respondents in the Royal College of General Practitioners' Oral Contraception Study. Logistic regression was used to evaluate associations between sociodemographics, lifestyle, and medical history and menopause type. RESULTS: Median age at natural menopause (n = 3650) was 49.0 years (interquartile range, 45.0-51.0), and at surgical menopause (n = 1463) was 42.4 years (38.0-46.4). Early natural menopause was associated with smoking, ever-use of oral contraception, sterilization, and history of endometriosis (all increased odds ratios) and ever-use of hormone replacement therapy (decreased). Surgical menopause was associated with manual social class, sterilization, and having a history of endometriosis, menorrhagia, or painful menstruation (all increased), and ever-use of hormone replacement therapy (decreased). CONCLUSION: Age at natural menopause was younger in this cohort than in other studies. More associations were found for surgical menopause than early natural menopause.