Sleep difficulty in women at midlife: a community survey of sleep and the menopausal transition.

OBJECTIVE: To compare age-adjusted and ethnic differences in prevalences of sleep difficulty at various stages of the menopausal transition and to determine the relative contribution of other factors, including vasomotor symptoms, sociodemographics, and psychological and physical health factors, to self-reported sleep difficulty in middle-aged women.
DESIGN: A community-based survey of women's health and menopausal symptoms was conducted between November 1995 and October 1997 at each of the seven US sites participating in the Study of Women's Health Across the Nation. A multiethnic sample of 12,603 Caucasian, African American, Chinese, Japanese, and Hispanic women aged 40 to 55 years was categorized into six groups: premenopausal, early perimenopausal, late perimenopausal, naturally postmenopausal, surgically postmenopausal, and postmenopausal receiving hormone replacement therapy. The women were asked whether they had experienced difficulty sleeping in the past 2 weeks.
RESULTS: Difficulty sleeping was reported by 38%. Age-adjusted rates were highest in the late perimenopausal (45.4%) and surgically postmenopausal (47.6%) groups. Among ethnic groups, rates ranged from 28% in Japanese women to 40% in Caucasian women. In the multivariate analysis, menopausal status was significantly associated with difficulty sleeping. Ethnicity, vasomotor and psychological symptoms, self-perceived health and health behaviors, arthritis, and education also were significantly associated with difficulty sleeping.
CONCLUSIONS: These results suggest that stage of the menopausal transition, independent of other potential explanatory factors, is associated with self-reported sleep difficulty. Older age per se was not significantly associated with difficulty sleeping.