Prevalence, frequency and problem rating of hot flushes persist in older postmenopausal women: impact of age, body mass index, hysterectomy, hormone therapy use, lifestyle and mood in a cross-sectional cohort study of 10 418 British women aged 54-65

Objective Hot flushes and night sweats (HFs/NSs) are the main menopausal symptoms, but few studies have been adequately powered to examine the dimensions or predictors of experiencing HFs/NSs. We report on these variables in a large UK cohort of postmenopausal women. Design Cross-sectional cohort study. Setting UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) cohort. Population A cohort of 202 638 postmenopausal women, aged 50-74 years, without oophorectomy, recruited to UKCTOCS between 2001 and 2005. Methods Women completed a follow-up questionnaire, and those aged 54-65 years were mailed a survey in July 2008. Main outcome measures Hot flush prevalence and hot flush rating scale. Results Of the 15 000 women mailed, 10 418 returned completed questionnaires; 90% had previously had HFs/NSs. Despite being on average 10 years postmenopausal, 54% experienced HFs/NSs (frequency of 33 per week with mean problem rating 4/10) that persisted across the age range. Past hysterectomy (OR 1.50, 95% CI 1.19-1.86), ever having smoked (OR 1.27, 95% CI 1.11-1.46) and alcohol consumption (current units) (OR 1.05, 95% CI 1.01-1.09) predicted ever having had HFs/NSs. Anxiety (OR 3.09, 95% CI 2.57-3.72), hysterectomy (OR 2.74, 95% CI 2.32-3.25), depressed mood (OR 1.57, 95% CI 1.24-1.99), years since last menstrual period (OR 0.95, 95% CI 0.94-0.96) and education (above and below 18 years) (OR 0.98, 95% CI 0.97-0.99) predicted the current prevalence of HFs/NSs. Few predictors of frequency were identified, but problem rating was associated with depressed mood, hysterectomy, skirt size increase and frequency of HFs/NSs. Past hormone therapy users who had discontinued treatment were more likely to have HFs/NSs that were more frequent and problematic. Conclusions To date, this is the largest UK study of the experience of HFs/NSs amongst older postmenopausal women. HFs/NSs are more prevalent in this age band than has previously been assumed. These findings and the associations of smoking, hysterectomy, anxiety, depressed mood and hormone therapy use with the experience of HFs/NSs have implications for prevention and symptom management.