In a 2015 JAMA Internal Medicine analysis of the Study of Women's Health Across the Nation, Nancy E. Avis and colleagues followed 3,302 women enrolled at seven US clinical sites through the menopause transition and found that, among the 1,449 women who reported frequent hot flashes or night sweats at any point, the median total duration of those symptoms was 7.4 years (Avis et al., JAMA Internal Medicine 2015; PMID 25686030). African American women in the cohort had the longest median duration at 10.1 years, longer than any other racial or ethnic group in the SWAN study.
The Avis team's verbatim summary: "Frequent VMS lasted more than 7 years during the menopausal transition for more than half of the women and persisted for 4.5 years after the FMP." FMP stands for final menstrual period. Half of the women in the analysis were still experiencing frequent vasomotor symptoms more than four years past their final period.
What SWAN is and why the Avis paper anchors the field
SWAN is the largest US longitudinal cohort study of the menopause transition. The 3,302-woman cohort enrolled at seven US clinical sites (Boston, Chicago, Detroit-area, Los Angeles, Newark, Oakland, and Pittsburgh) is multiracial and multiethnic by design; the racial and ethnic distribution at enrollment was approximately 47 percent White, 28 percent African American, 9 percent Chinese, 9 percent Japanese, and 8 percent Hispanic. The cohort recruited women aged 42 to 52 and has followed them through the menopause transition with annual visits since 1996.
The Avis 2015 paper is the SWAN duration-of-symptoms anchor. Before publication, the field's working assumption was that hot flashes and night sweats lasted a few months to a few years for most women. The Avis median of 7.4 years overall and 10.1 years among African American women reset that assumption and is now cited extensively in US menopause-care guidelines.
Why the 10.1-year median matters specifically for Black women
A 10.1-year median means half of African American women with frequent vasomotor symptoms experience them for longer than a decade. The Avis cohort's design accounts for the multiracial distribution; the 10.1-year figure is not an artifact of small subgroup sampling. Black women in the United States enter the perimenopausal transition with a higher cardiovascular-risk-factor profile than white women of the same age (higher rates of hypertension and obesity per CDC data) and complete the transition with an even larger gap. The American Heart Association's 2020 scientific statement on menopause and cardiovascular risk frames the menopause transition as a CVD-risk-acceleration window. A decade-plus of frequent vasomotor symptoms is a decade-plus of an unstable cardiovascular system that is also under-screened for the risk acceleration that comes with menopause.
Our coverage of Halle Berry's ReSpin platform and the Black-women menopause care gap covers the consumer-anchor side of the same evidence base. The Avis paper is the cohort-evidence layer that anchors Berry's advocacy and the broader Black-women menopause-care conversation.
What the paper does and does not tell you
The Avis median is total duration of frequent vasomotor symptoms, defined in SWAN as hot flashes or night sweats six or more days in the prior two weeks at any visit. The paper does not stratify symptom severity by race within the duration analysis; some women with 10.1-year durations had moderate symptoms most years, others severe symptoms. The paper also does not test treatment effects; SWAN is observational. What works to shorten the duration, or reduce the burden during the duration, is the subsequent treatment-trial literature, not Avis 2015.
Two limitations are worth naming. The SWAN cohort enrolled women aged 42 to 52 in 1996 to 1997; generalizing the duration finding to women entering perimenopause in 2026 carries the assumption that vasomotor-symptom duration has not shifted across cohorts, which is a working assumption rather than a tested one. The seven SWAN sites are all urban or peri-urban; rural African American women may have different symptom-duration profiles given different healthcare-access patterns.
How to talk to your clinician about the menopause transition
Two specific things to bring to a perimenopause-age primary-care or OB-GYN visit.
First, ask the clinician to document the timing and frequency of your vasomotor symptoms across visits. The phrasing: "Can we track my hot-flash and night-sweat frequency across this visit and the next several visits, since SWAN data shows Black women's symptoms can last a decade or longer?" The Avis median is the documentation argument. A clinician who knows the 10.1-year figure for African American women is more likely to plan the care relationship across the duration rather than treat the symptoms as a short-term issue.
Second, ask about the cardiovascular-risk-screening conversation. The phrasing: "Given the AHA 2020 statement that menopause is a cardiovascular-risk-acceleration window, what blood pressure, lipid, and metabolic screening do you recommend over the next several years specifically?" Cardiovascular-risk acceleration is not separate from the vasomotor-symptom-duration finding; the same hormonal transition that drives the symptoms also drives the cardiovascular shift. Asking about CVD screening as part of the menopause-care conversation pulls the two together.
The Black Health provider directory lists OB-GYNs and internal-medicine clinicians with verified active licenses, plus family-medicine clinicians who treat midlife as a load-bearing care window rather than a deferral target.
Citations
- Avis NE, Crawford SL, Greendale G, Bromberger JT, Everson-Rose SA, Gold EB, Hess R, Joffe H, Kravitz HM, Tepper PG, Thurston RC; Study of Women's Health Across the Nation. Duration of menopausal vasomotor symptoms over the menopause transition. JAMA Internal Medicine. 2015;175(4):531-539. PMID 25686030.
