The Study of Women’s Health Across the Nation (SWAN), assessed the transition through menopause among 3302 women who were enrolled at 7 US sites. Spanning February 1996 to April 2013, the research included 1449 women with frequent VMS, considered to be ≥6 days in the previous 2 weeks. All of the participants completed a median of 13 visits during the study.
Median total VMS duration was 7.4 years. In the 881 women who had an observable final menstrual period (FMP), the VMS persisted after FMP for a median of 4.5 years. Total VMS duration and post-FMP persistence were longest (median >11.8 years and median 9.4 years, respectively) in women who first reported frequent VMS when they were premenopausal or perimenopausal. Conversely, women who first experienced frequent VMS in postmenopause had the shortest total VMS duration (median 3.4 years). Total VMS duration was longest—median 10.1 years—in African-American women, compared to those in other racial/ethnic groups.
Other factors related to longer VMS duration, total duration or post-FMP persistence were younger age, lower educational level, higher depressive symptoms and anxiety at first report of VMS, and greater perceived stress and symptom sensitivity.
The researchers concluded that frequent VMS lasted over 7 years during the menopausal transition in more than half of the studied women and persisted for 4.5 years after FMP. They urged healthcare providers to counsel their patients on the potentially long duration of frequent VMS, particularly in African-American women.