Variability of bothersome menopausal symptoms over time – a longitudinal analysis using the Estonian postmenopausal hormone therapy trial (EPHT)
BMC Women's Health
Variability of bothersome menopausal symptoms over time - a longitudinal analysis using the Estonian postmenopausal hormone therapy trial (EPHT)
Elina Hemminki 0
Elena Regushevskaya 0
Riitta Luoto 2
Piret Veerus 1
0 National Institute for Health and Welfare (THL) , P.O. Box 3000271, Helsinki , Finland
1 Department of Epidemiology and Biostatistics, National Institute for Health Development , Hiiu 42, 11619, Tallinn , Estonia
2 UKK Institute for Health Promotion Research and National Institute for Health and Welfare (THL) , P.O. Box 3033501, Tampere , Finland
Background: Very little data are available on the natural course or level of disturbance of vasomotor symptoms among middle-aged women. Using readily collected trial data we studied the persistence of vasomotor symptoms among untreated women. Methods: In a trial comparing combined hormone therapy to placebo or no treatment (control groups), a cohort of women aged 50-59 at recruitment were followed annually by questionnaires. Women in the control groups (n = 486) were grouped by the number of years followed, with the prevalence and severity of symptoms calculated both cross-sectionally and longitudinally. Results: About two thirds of the women (67%) reported vasomotor symptoms and half (46%) bothersome symptoms at recruitment. In the cross-sectional analysis, their prevalence declined between recruitment and 1-year follow-up (32% bothersome symptoms) and 2-year follow-up (27%). Thereafter it remained about the same level. In the longitudinal analysis, there was a notable variation in the prevalence of disturbing vasomotor symptoms over time, time entering the study and the compliance to the surveys. In the two groups having most follow-up times, the proportion of women with bothersome symptoms first increased and then decreased. Conclusions: There was a notable variability in the development of disturbing vasomotor symptoms over time in a selected group of women aged 50-59. Population-based follow-up studies of untreated women would be useful to estimate the symptom burden.
Menopausal symptoms; Duration; Follow-up; Estonia
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Background
A number of studies have reported a high prevalence of
vasomotor symptoms among middle-aged women [1-5].
In a large review by the National Institutes of Health [6],
1451% of premenopausal and 3080% of peri- and
postmenopausal women reported hot flashes and night
sweats. However, not all women consider hot flushes
bothersome [5,7-10]. Sleep disturbances are common
among all menopausal women (occurring in 1642% of
premenopausal, 3947% of perimenopausal and 3560%
of postmenopausal women). In a Finnish
populationbased study by Hemminki et al. (1995), 28% of women
aged 4564 years reported hot flushes, 38% reported
tiredness and 27% different kind of pains (head-, back-,
and joint ache). The probability of other symptoms is
higher if the woman has vasomotor symptoms [7,11].
Cross-sectional surveys among women of different
ages show that hot flushes are most common soon after
menopause, but they occur even after 10 years
[7,8,12,13]. Some women have not flashes even before
menopause [13-15], and among some women they
become bothersome only some years after menopause [13].
The consensus around vasomotor symptoms (hot
flushes and sweating) and vaginal drynessthough not
for other symptomsis that they are more common
during menopause than before or after it [2,6,9,16-18].
Results conflict as to whether or not other complaints
are more common around menopause [16] or whether
the observed increase is related to age rather than to
menopause [2,19].
Very few studies grade the symptoms according to
womens experience of disturbance or what is their
patterning [20]. The purpose of this study was to use readily
collected data on control women in a hormone therapy
trial to study how bothersome vasomotor symptoms are
for women and what is their patterning. Originally we
had also planned to study their duration, but the
available data did not allow that.
Methods
This is a cohort study based on yearly follow-up
questionnaires sent to control women of a trial comparing
combined hormone therapy to either placebo or nothing
(the control groups) [21]. Women were recruited in
Estonia from 19992001, and followed by annually
mailed questionnaires in 20002004. Detailed
descriptions of the recruitment, inclusion and exclusion criteria,
trial treatment, adherence, follow-up and trial outcomes
as well as the content of information leaflets and trial
questionnaires have been published elsewhere [21-24].
In the following the main features relevant to this study
are described.
A recruitment questionnaire was mailed in 19981999
to all women aged 4564 in two Estonian counties (n =
39 713); the identification was through the Estonian
Population Registry. Of the 14 743 women who returned
the questionnaire, 6606 respondents were interested in
participating in a randomised trial, of which 4295
women were found to be eligible accordi (...truncated)