AN EVENT HISTORY ANALYSIS OF AGE AT LAST MENSTRUAL PERIOD - CORRELATES OF NATURAL AND SURGICAL MENOPAUSE AMONG MIDLIFE WISCONSIN WOMEN

Population aging coupled with heightened consumerism among those using the health care system have increased public and research interest in menopause. Despite these trends, we know little about the process of menstrual cessation. This paper reviews previous claims regarding secu lar trends in menopausal age by considering how menstrual cessations d iffer by type: (1) that due to surgical intervention such as hysterect omy, and (2) that due to ''natural'' (non-surgical) menopause. Analyse s of menopause that exclude hysterectomized women are flawed, because such women constitute a high proportion of American women at midlife. Competing risk survival analysis techniques are applied to model the s hape of the underlying hazards for reproductive organ surgery versus ' 'natural'' menopause among 3506 midlife women from the Wisconsin Longi tudinal Study. Weibull models are used to evaluate effects of a variet y of possible correlates (including education, mental ability, occupat ion, family background, fertility experience, smoking behavior and hor mone therapy). While socioeconomic parameters do contribute to observe d differences in age at menstrual cessation, these factors operate thr ough more proximate health-related behaviors (such as smoking in the c ase of natural menopause and fertility for surgical menopause). (C) 19 98 Elsevier Science Ltd. All rights reserved.