Factors associated with resilience or vulnerability towards hot flushes and night sweats during the menopausal transition
Running title: Resilient or vulnerable to menopause symptoms
Oonagh K Duffy PhD 1 , Lisa Iversen PhD 1 , Lorna Aucott PhD 2 and Philip C Hannaford MD 1 .
From
1
Academic Primary Care,
2
Medical Statistics Team, Division of Applied Health
Sciences, University of Aberdeen, UK.
Funding sources: The postal survey was funded by the University of Aberdeen
Conflicts of interest/disclosures: Academic Primary Care has received payments from Wyeth
Pharmaceuticals for lectures related to hormone therapy provided by PCH. OKD, LI and LA have nothing to declare.
Corresponding author: Lisa Iversen, PhD,
Academic Primary Care
Division of Applied Health Sciences
University of Aberdeen
Polwarth Building
Foresterhill
Aberdeen
AB25 2ZD, UK
Telephone number: +44 (0)1224 437212
Fax number: +44 (0)1224 437285
Email: l.iversen@abdn.ac.uk

Abstract
Objective : To explore factors associated with “resilience” and “vulnerability” to hot flushes and night sweats.
Methods : 4407 women aged 45-54 recruited from family practices in northeast Scotland responded to a postal questionnaire. Among respondents reporting high frequency hot flushes
(n=628) or night sweats (n=628), we compared those with low level of bother (“resilient”) with the rest. Similarly, among women reporting low frequency hot flushes (n=459) or night sweats (n=459) those with high bother (“vulnerable”) were compared with the rest. Forward stepwise logistic regression examined social, psychological and physical factors associated with resilience or vulnerability to each symptom.
Results : Women resilient to hot flushes: had previously not been bothered by their menstrual periods; were not experiencing somatic symptoms or night sweats; perceived their symptoms as having low consequences on their lives. Those vulnerable to hot flushes: had children; a high body mass index; reported night sweats; perceived their symptoms as having high life consequences. Women resilient to night sweats were: non-smokers; not experiencing sleep difficulties; not using psychological symptom management strategies; perceived their menopausal symptoms as having low life consequences. Those vulnerable to night sweats had: low educational attainment; previously been bothered by their menstrual periods; below average physical health; reported musculo-skeletal symptoms and hot flushes; perceived their menopausal symptoms as having high life consequences.
Conclusion : Factors associated with resilience or vulnerability differed by symptom studied, although relationships with illness perceptions existed in all models. Our results suggest that a single approach to managing these symptoms is likely to be unsuccessful.
Key words : Community, illness perceptions, menopause, hot flushes, night sweats

Introduction
So far, most research into menopausal symptoms has focussed on the frequency of various symptoms experienced by women during each stage of the menopause transition, associated levels of bother and use of different symptom management strategies. Often a particular emphasis has been on those experiencing a high frequency of symptoms, or using particular forms of healthcare (such as hormone therapy, HT). There is, however, growing interest in understanding why some women appear to be untroubled by their symptoms, or report having a good quality of life during the menopausal transition
1
. Better understanding of the psychological, physical and social factors associated with apparent resilience towards symptoms may help identify new interventions for women needing help.
Resilience is a psychological concept which has been described as ‘patterns or processes of positive adaptation and development in the context of significant threats to an individual’s life or function’ 2 . Although few would argue that the menopause transition is a significant threat to a woman’s life, it is a time when many women report bothersome symptoms 3 , which persist for a number of years
4
and, are associated with health related quality of life
5,6
.
The Study of Women’s health Across the Nation (SWAN), used data from the seventh annual interview of participating women to examine factors associated with discrepancies between reported frequency of, and bother from, hot flushes or night sweats
7
. Women who reported frequent hot flushes and low levels of bother were more likely to be married and less likely to have negative affect than those reporting a similar frequency of hot flushes and high levels of bother. Women who reported high frequency of night sweats but low levels of bother were more likely to be married, less likely to report sleep difficulties and less likely to be late perimenopausal than women reporting high frequency of night sweats and high levels of bother. In contrast, women who reported low frequency from hot flushes and high levels of bother were more likely to be African American (compared with White women), to report their self-rated health as poor and have a lower level of educational attainment. Women reporting low frequency but high levels of bother for night sweats were also more likely to report poor self-rated health. These results suggest that it may be possible to identify women
‘resilient’ or ‘vulnerable’ to the impact of menopausal symptoms. A recent study of
Ecuadorian women found that lower scores on the Wagnild and Young Resilience Scale
(indicating less resilience) correlated with more severe hot flushes 8 .

Rutter pointed out that resilience is likely to reside in the social context as much as within the individual
9
. Thus, social circumstances and support, self esteem and self-efficacy are likely to be important determinants of resilience. Other influences among menopausal women may be attitudes to the menopause
10
and illness perceptions or representations
11
of menopausal symptoms. The aim of this study was to determine, using data from a large community-based study of women living in the United Kingdom, factors associated with resilience and vulnerability to menopausal symptoms. Our hypothesis was that women apparently resilient to menopausal symptoms (i.e. those experiencing a high frequency of hot flushes or night sweats but reporting a low level of associated bother) would have positive attitudes towards the menopause, low levels of anxiety or depression, high levels of social support, and positive illness perceptions. Conversely, it was hypothesized that apparently vulnerable women (i.e. those reporting a low frequency of symptoms but high level of bother), would have results for these characteristics in the opposite direction.
Methods
Ethical approval for the study was granted from the East of Scotland Research Ethics Service
(reference 08-S1401-129).
The main methods, and prevalence of menopausal symptoms, have been reported elsewhere
3
.
Briefly, 16 general (family) practices across north east Scotland each randomly sampled just over 500 (to allow for exclusions) women aged 45 to 54 years from their list of registered patients. A study pack containing an invitation letter signed by the general practitioner, information sheet, consent form, self-completion questionnaire entitled “Women’s Health in
Midlife” and a postage prepaid envelope, was sent to 8,206 eligible women. Non-respondents were sent an identical study pack three weeks after the initial mailing. The age and socioeconomic status (as determined by the Scottish Index of Multiple Deprivation; SIMD)
12
of all eligible women was obtained from the practice lists to allow comparison between respondents versus non-respondents.
The questionnaire collected data about: age; marital status; educational level (none; O grades or equivalent; Highers or equivalent; College qualification; degree or professional qualification; post-graduate qualification) employment status; current height and weight (to allow calculation of BMI); menopausal status; previous hysterectomy and/or ovarian surgery; other significant medical history; a six item version of the Multidimensional Scale of

Perceived Social Support
13
; the Short Form-12 Health Survey, version 2 (SF-12v2)
14
; the
Hospital Anxiety and Depression Scale (HADS)
15
; the Attitude Towards Menopause checklist (ATM)
16
; a symptom checklist; questions about frequency of hot flush and night sweats per day and/or per week
17
; questions relating to social support; a management strategy for symptoms checklist; and a 14-item version of the Illness Perception Questionnaire-
Revised (IPQ-R)
18
. The symptom checklist included 23 symptoms commonly experienced around the menopause. Respondents were asked to indicate whether they had experienced each symptom in the last month, and if yes, the level of bother from that symptom and whether they attributed it to the menopause.
Statistical analysis
The data were analysed using SPSS (version 19). In accordance with the staging system of menses recommended by the Stages of Reproductive Aging Workshop (STRAW)
19
, respondents were classified as: premenopausal if they reported that their menstrual periods had not changed in the last few years, perimenopausal if they reported that they were experiencing menstrual cycle irregularities but had not gone 12 months in a row without a period, and postmenopausal if they had not had a period in the last 12 months. Respondents who reported having had a hysterectomy and/or oopherectomy were classified as having a surgical menopause ( surgically menopausal ). Women who were using the intrauterine system
(Mirena), who began HT whilst still menstruating, who had an endometrial ablation or who had missing data about menstrual periods were regarded as “ unclassifiable
” with respect to menopausal status.
To facilitate the interpretation of findings, a number of covariates were categorised for analysis. Education into: no education or O grades; highers or college qualification; degree or postgraduate qualification. Employment into: not employed; part-time employment; selfemployed; full-time employment. BMI into: <25kg/m 2 ; 25-30kg/m 2 ; >30kg/m 2 . Smoking status as: never-; current-; ex-smokers. Alcohol consumption into: <7; 7-14; >14 units per week. Frequency of exercise and strenuous exercise into: rarely or <once a week; once or 2-3 times a week; 4-6 times a week or every day. Self-assessed health into: excellent; very good; good; fair or poor (combined). Mental and physical health summary scores from the SF-12v2 into: ≤median; > median value. Social support from friends, family or a significant other into: low; moderate; high - based on the distribution of tertile scores from the MSPSS. Scores of
≥8 on the anxiety (HADS-A) or depression (HADS-D) subscales of the HADS were used to

categorise respondents into those who had a possible case of anxiety or depression, respectively. Attitudes towards menopause were categorised into: positive; neutral; negative- based on the distribution of tertile scores for the sample, with the highest tertile representing positive attitudes. Scores on the illness perceptions scale were also categorised according to score tertiles: high; moderate and low.
Symptom management strategies were categorised into four groups- psychological: currently talking to family and friends, talking to a health professional, relaxation; prescription: currently using HT, anti-depressants, clonidine, oestrogen creams; complementary alternative medicine: currently using herbal remedies, vitamins, acupuncture or reflexology; and lifestyle: avoiding caffeine, wearing cotton clothes, sleeping in a cool room, exercising, using lubricants.
To simplify the inclusion of symptoms in the models, factor analysis was used to group the
23 symptoms into six symptom clusters: psychological (depression, tearfulness, mood swings, anxiety), sexual difficulties (vaginal dryness, decreased sexual interest), general somatic (breathlessness, passing urine more frequently, headaches/migraine, dizziness, leakage of urine), musclo-skeletal (stiff joints, aches and pains), menstrual (irregular periods, heavy periods), and bloating symptoms (increased weight, feeling bloated). The name of each cluster was based on the general characteristics of symptoms included in it. Although hot flushes, night sweats and sleep difficulties formed a separate symptom cluster, we did not group these symptoms together in our analyses since we wanted to investigate hot flushes and night sweats separately.
Based on the distribution of responses from all respondents reporting hot flushes, women were grouped by frequency of hot flushes per week into: 1 to 7 (low) and ≥15 flushes (high).
Similar to the analysis conducted by SWAN 7 , we did not include in our analyses women with moderate frequency of hot flushes (8-14 per week), as our hypotheses related only to women with high and low frequency symptoms. Women were grouped by frequency of night sweats per week into: 1 to 5 (low); ≥6 night sweats (high). Reported level of bother from each symptom was used to group respondents into: not at all/slightly (low); moderately/quite a bit/extremely bothered (high).

Cross tabulations were then constructed from the responses of perimenopausal, postmenopausal and surgically menopausal women who provided information about both frequency and level of bother from each symptom, to identify respondents deemed “resilient”
(i.e. reporting high frequency and low levels of bother) or “vulnerable” (i.e. reporting low frequency and high levels of bother) to their hot flushes or night sweats.
Hot flushes and night sweats were reported by some premenopausal women, but a much lower frequency than among perimenopausal, naturally postmenopausal or surgically menopausal women.
3
Fewer premenopausal women were bothered by these symptoms or attributed them to the menopause. This suggests a marked difference between premenopausal and other groups in symptom experience and effect, and by implication possible factors associated with resilience and vulnerability. These differences lead us to exclude premenopausal women from our analyses.
Four models were constructed comparing resilient or vulnerable women with women experiencing the same frequency of symptom but opposite level of bother (see Figure 1 and
2). For example, women apparently resilient to hot flushes (high frequency, low bother) were compared with women with high frequency of hot flushes and high levels of bother. Chisquared or Mann-Whitney tests were used to identify statistically significant univariate associations between socio-demographic, psychosocial and physical variables included in the questionnaire previously shown to be associated with menopausal symptoms experience
(namely socio-economic status
6,20,21
, employment
22-24
, BMI
6,21,25,26
, exercise
21-23
, smoking 21,22,23,27 , alcohol consumption 23,28,29 , educational attainment 20,23 , history of hysterectomy and/or oophorectomy
23,30,31
, health related quality of life
6,32,33
, marital status 11,21 , past medical history 6 , self-rated health 20,29 , attitudes to menopause 10 , social support 28 and illness perceptions 11 ) and resilient or vulnerable group membership.
Variables showing significant association at the p<0.05 level in any group were then entered into forward stepwise logistic regression models to identify the variables independently associated with resilience or vulnerability to hot flushes or night sweats. In addition to including statistically significant variables, management strategies and illness perceptions were forced into the final models, even if not statistically significant. This was done to enable the effect of management strategies and illness perceptions to be examined among women who appear to be resilient or vulnerable to hot flushes or night sweats. We wished to look at

the use of different management strategies because of comparatively recent changes in clinical guidance regarding the use of HT. We were also interested to see if illness perceptions were associated with menopausal symptoms, as this may help identify novel ways for managing symptoms. Interactions between variables with significant independent associations in the multivariate models were tested for.
Results
Ninety-five women did not receive their invitations to participate as their study packs were returned by the mail service undelivered. Removing these women from the denominator we had a corrected response rate of 55% (4445/8111). After exclusions data were available for
4407 women.
The median age of respondents was 49 years (interquartile range 47 to 52). Roughly two fifths of the respondents had three or more pregnancies (40%) and two children (43%, Table
1). Most of the sample (78%) was married or cohabiting. Almost a third of respondents were educated to degree level (29%), or secondary school level (26%). Nearly half of the women were in full time paid employment (49%).
A quarter of the respondents were premenopausal; 28% perimenopausal; 22% postmenopausal; 14% surgically menopausal; and 12% “unclassifiable”. Hot flushes were experienced by 46.7% (95% CI 45.2 to 48.2) of women, and night sweats 46.4% (95% CI
44.9 to 47.9).
Among the 628 women who reported a high frequency of hot flushes, 92 (14.6%) reported low levels of bother (i.e. appeared to be “resilient”: Table 2, box with dotted boundary). This subgroup of women was compared in the multivariate models with the remaining 536
(85.4%) who reported high levels of bother. Of the 459 women who reported low frequency of hot flushes, 217 (47.3%) reported high levels of bother (i.e. appeared to be “vulnerable”:
Table 2, box with a solid boundary). This subgroup was subsequently compared with the remaining 242 (52.7%) women with low levels of bother from their hot flushes. Among the
794 women who reported a high frequency of night sweats, 145 (18.3% reported low levels of bother (i.e. deemed “resilient”: Table 3 box with dotted boundary). This subgroup was compared with the remaining 649 (81.7%) women who reported high levels of bother. Of the
459 women who reported low frequency of night sweats, 225 (49.0%) women reported high

levels of bother (i.e. appeared to be “vulnerable”: Table 3, box with a solid boundary). This subgroup was compared with the remaining 234 (51.0%) women with low levels of bother. It is noteworthy that a larger proportion of women appeared to be vulnerable than resilient to either symptom.
Univariate associations
Several socio-demographic, psychological and lifestyle variables showed a significant univariate association in at least one of the four models investigating factors associated with being resilient or vulnerable to hot flushes and night sweats.
“Resilience” to hot flushes
Significant univariate associations with resilience to hot flushes were found for: number of pregnancies; number of children; educational attainment; BMI; smoking status; alcohol consumption; frequency of exercise; perceived severity of previous menstrual periods; anxiety and depression (as assessed by HADS
12
); health related quality of life (SF-12v2 physical and mental summary scores); reporting psychological, somatic, musculoskeletal, bloating symptoms, night sweats, sleep difficulties; attitudes towards menopause, current use of complementary alternative medicines, prescription medicines, psychological strategies, lifestyle changes for symptoms attributed to the menopause; and perceived consequences of hot flushes (illness perceptions) – data not shown.
“Vulnerability” to hot flushes
Factors significantly associated with vulnerability to hot flushes were: number of pregnancies; number of children; educational attainment; BMI; smoking status; alcohol consumption; perceived severity of menstrual periods; frequency of exercise; anxiety and depression; health related quality of life; reporting somatic, psychological, musculoskeletal, bloating symptoms, night sweats, sleep difficulties; attitudes towards menopause; current use of complementary alternative medicines, prescription medicines, psychological strategies, lifestyle changes for symptoms attributed to the menopause; and perceived consequences of hot flushes (illness perceptions).

“Resilience” to night sweats
Factors significantly associated with resilience to night sweats on univariate analysis were: number of pregnancies; number of children; educational attainment; BMI; smoking status; alcohol consumption; frequency of exercise; perceived severity of menstrual periods; anxiety and depression; health related quality of life; reporting somatic, psychological, musculoskeletal, bloating symptoms, hot flushes, sleep difficulties; attitudes towards menopause; current use of complementary alternative medicines, prescription medicines, lifestyle changes, psychological strategies for symptoms attributed to the menopause; and perceived consequences of night sweats (illness perceptions).
“Vulnerability” to night sweats
Before adjustment, factors significantly associated with vulnerability to night sweats were: number of pregnancies; number of children; educational attainment; BMI; smoking status; alcohol consumption; frequency of exercise; perceived severity of previous menstrual periods; anxiety and depression; health related quality of life; reporting somatic, musculoskeletal, psychological, bloating symptoms, hot flushes, sleep difficulties; attitudes towards menopause; current use of complementary alternative medicines, prescription medicines, psychological strategies, lifestyle changes for symptoms attributed to the menopause; and perceived consequences of night sweats (illness perceptions).
Multivariate models
Factors independently associated with “resilience” to hot flushes
In the multivariate analysis, women who reported being previously bothered by their menstrual periods were significantly less likely to be in the “resilient” to hot flushes group than their reference counterparts, as were: those who reported experiencing one, two or three somatic symptoms, those reporting night sweats; and those who perceived their menopausal symptoms to be having high consequences on their lives (Table 4). Forcing the inclusion of management strategies and illness representations into the final model did not tend to change the odds ratios, in this or the other models.

Factors independently associated with “vulnerability” to hot flushes
Women who reported having one or more children were significantly more likely to be in the
“vulnerable” to hot flushes group than those in the reference group, as were: women with a
BMI of 30 or more; those also reporting night sweats; and those who perceived their menopausal symptoms to be having moderate or high consequences on their lives (Table 5).
Factors independently associated with “resilience” to night sweats
Table 6 shows that women who reported being a current smoker were significantly less likely to be in the “resilient” to night sweats group, than those in the reference group, as were: those reporting sleep difficulties; those using psychological strategies to manage their menopausal symptoms; and those who perceived their menopausal symptoms to be having moderate or high consequences on their lives.
Factors independently associated with “vulnerability” to night sweats
Women who reported being bothered by menstrual periods in the past were more likely to be in the “vulnerable” to night sweats group, than those in the corresponding reference group, as were those: with a below median SF-12v2 physical health summary score; those also reporting hot flushes; those with one or two musculo-skeletal symptoms; and those who perceived their menopausal symptoms to be having high consequences on their lives (Table
7). In contrast, women who had a degree or postgraduate level of education were significantly less likely to be in the “vulnerable” to night sweats group.
No significant interactions were found for factors independently associated with resilience or vulnerability to hot flushes or night sweats.
Figures 1 and 2 summarise the factors found to be independently associated with resilience or vulnerability to hot flushes and night sweats, respectively.
Discussion
We wished to identify the characteristics of women who appeared to be resilient or vulnerable to the effects of hot flushes or night sweats. We were able to include a wide range of personal bio-psycho-social characteristics in our analyses. Factors independently associated with different group membership included: having had children, smoking, education, self-reported poor physical health, history of menstrual problems, different

symptoms (somatic symptoms, night sweats, hot flushes, sleep difficulties, musculoskeletal symptoms) and the perceived consequences of menopausal symptoms. The characteristics of women differed in each multivariate model, except for “perceived consequences” which emerged as an independent factor in each model. Some factors were notable for their absence in the final models - including social support and marital status. However, it should be noted that almost 80% of women in our study were married and so we lacked power to examine the effect of marital status on resilience and vulnerability to hot flushes and night sweats.
There has been only one other community-based study looking at this issue with similar depth, conducted in North America
7
. In contrast to that study, marital and menopausal status was not found in our study to be independently associated with resilience to hot flushes or night sweats, and poor self-rated health was not independently associated with vulnerability to either symptom. On the other hand, as in SWAN
7
, women resilient to night sweats in our study were less likely to report sleep difficulties. Educational attainment was associated with vulnerability to hot flushes in SWAN, whereas in our study this variable was associated with vulnerability to night sweats. Differences between studies may be due to how educational attainment and self-rated health were assessed, or the influences of these factors in different countries. Further studies are needed to build the evidence base of factors associated with resilience or vulnerability to these and other menopausal symptoms.
A common factor in all the models was the respondents’ perceptions about the consequences of their symptom on their lives (one aspect of illness representations). Women who perceived their menopausal symptoms as having little consequence on their lives were more likely to be in the “resilient” group of either symptom, whereas those with perceptions of moderate or high consequences were more likely to be in the “vulnerable” group. The relationship between perceptions about the consequences of symptoms and vasomotor symptom experience has not been reported before. However, women‘s perceptions about the consequence of their menopausal symptoms have been linked with help seeking behaviour; women reporting negative consequences have been found to be more likely to have visited their doctor recently than women with less negative illness perceptions
34
. Our results suggest that illness representations may influence the impact of menopausal symptoms. It is important to note that illness representations can be changed
35,36
, suggesting a novel way for helping some women to manage their menopausal symptoms, perhaps through psychoeducational programmes for menopause management
36
or challenging negative perceptions

about symptoms through group cognitive behavioural therapy
37,38
. Future studies of the menopause transition should include a measure of illness perceptions.
Methodological strengths and weaknesses
One of the main strengths of our study was its community base. Results from this study are more likely to be representative of women living in the community than those from studies using samples from healthcare settings, such as gynaecological clinics 39-41 .
The analyses assume that frequency of symptoms and reported associated level of bother correctly differentiated women into those who, if asked directly, perceive themselves as
“resilient” or “vulnerable” to the effects of these menopausal symptoms. A strength of our approach is that it moves away from groupings based on help seeking behaviour for symptoms
42
. Consulting a health care professional may not always identify women resilient or vulnerable to their symptoms, since a proportion of women bothered by their symptoms do not to consult their doctor
43
. Indeed in our study only one of the five different types of management strategy examined emerged as an independent variable in one of our multivariate models (not currently using psychological strategies and “resilience” to night sweats). This indicates, at best, only a weak relationship between help seeking behaviour and resilience or vulnerability to symptoms. Although work is needed to ascertain whether our assumptions about our ability to accurately allocate women to appropriate groups are correct, we believe our study provides an important addition to the paucity of information about resilience and vulnerability during the menopausal transition.
The inclusion of information about illness perceptions was novel. In our study we adapted the Illness Perception Questionnaire-Revised, after consulting with one of the individuals
(Professor John Weinman) who devised the original measure. The adapted questionnaire included two items for each domain, in order to restrict the size of the questionnaire; and referred to menopausal symptoms rather than illness throughout, since many women are unlikely to regard the menopause as an illness. Although perceived consequences of menopausal symptoms emerged as a significant factor in all four models, none of the other psychological elements emerged as important. This may have been because we only included two items per domain in our version of the IPQ-R. Although further work is needed to test the validity of our IPQ-R, our observations show that psychological factors probably have an important role in symptom experience and so should be measured.

Like others
44,45
, we categorised women who had a hysterectomy separately as surgically menopausal. We did this even although women who had the operation without concomitant bilateral oophorectomy will not have had an immediate cessation of ovarian function. In our study, among women with hysterectomy roughly two thirds (65.4%) reported having a hysterectomy without bilateral oophorectomy. We have previously shown that women classified as surgically menopausal in this way had a similar frequency of hot flushes and night sweats, and a similar level of associated bother, as women postmenopausal from natural causes 3 . This pattern occurred even though more surgically menopausal women were current users of HT than naturally postmenopausal women (21% versus 8%, respectively). It is likely, therefore, that a high proportion of women classified in our study as surgically menopausal had cessation of ovarian function. This concurs with other research which has reported that hysterectomy with ovarian conservation in premenopausal women is associated with loss of ovarian function almost four years earlier than women without hysterectomy
46
.
Differences in use of hormone therapy, or other medications, was allowed for in the statistical models and so cannot explain our findings.
Our questionnaire response rate of 55% was less than desired, although higher than those achieved by others in recent UK-based lifestyle surveys 44 . Respondents were significantly more affluent than non-respondents
3
. Response bias, therefore, may have occurred. Some studies have found that women from lower socio-economic groups report more menopausal symptoms than those from higher socio-economic groups
6,20-21
. Alternatively, women experiencing menopausal symptoms may have been more likely to complete the questionnaire than asymptomatic recipients. Although response bias might have influenced our estimates of hot flushes and night sweats prevalence, it is unclear how this might have affected our comparisons of resilience and vulnerability. A further limitation of our work was its cross-sectional nature. Whilst it was possible to investigate different patterns of associations, temporal sequences of cause and effect could not be established. Furthermore, although a wide range of socio-demographic, physical and psychological variables were assessed in the questionnaire, others, such as diet, were not because of a wish to avoid response fatigue. Some of the associations, therefore, may be due to confounding. A further limitation was the investigation of numerous variables, making the study potentially prone to type I errors. On other hand some of the comparisons were based on a small number of

women with the outcome of interest so some factors related to resilience or vulnerability may not have been detected.
Conclusion
Although our results should be interpreted with caution they suggest that factors associated with resilience or vulnerability to the classic menopausal symptoms of hot flushes and night sweats differ, depending on the symptom studied. Only one factor was common to all models examined: respondents’ perceptions of the consequences of their symptoms. Future studies of the menopause should consider the role of participants’ illness perceptions, as these may play a role in how women experience and manage menopausal symptoms.

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Figure legends
Figure 1. Summary of factors found in the fully adjusted model to be associated with
"resilience" or "vulnerability" to hot flushes
Figure 2. Summary of factors found in the fully adjusted models to be associated with
“resilience" or "vulnerability” to night sweats

Table 1. Socio-demographic characteristics of respondents
Characteristic
Age (N = 4407)
45
46
47
48
49
50
51
52
53
54
Number of pregnancies (N = 4217)
0
1
2
≥3
Number of children (N = 4314)
0
1
2
≥3
Marital status (N = 4369)
Single
Partner, not living together
Married / cohabiting
Divorced / separated
Widowed
Body Mass Index (BMI), kg/m 2 (N= 4111)
<18.5 (Underweight)
18.5-24.9 (Normal weight)
25.0 -29.9 (Overweight)
≥30.0 (Obese) n (%) a
400 (9.1)
496 (11.3)
464 (10.5)
464 (10.5)
463 (10.5)
511 (11.6)
497 (11.2)
501 (11.4)
474 (10.8)
(3.1) 137
600 (14.2)
488 (11.6)
1443 (34.2)
1686 (40.0)
732 (17.0)
618 (14.3)
1847 (42.8)
1117 (25.9)
243
128
(5.6)
(2.9)
3421 (78.3)
498 (11.4)
79 (1.8)
48 (1.2)
1756 (42.7)
1319 (32.1)
988 (24.0) a Denominator excludes women with missing data

Table 1. (cont.) Socio-demographic characteristics of respondents
Characteristic
Educational attainment (N= 4338)
No educational qualifications
‘O’ Grade / ‘O’ Level / Standard Grade
Higher / ‘A’ Level / National Grade
College qualification
Degree / professional qualification
Post-graduate qualification
Employment status (N= 4372)
Full-time job (≥30 hrs a week)
Part-time job (<30 hrs a week)
Self-employed
Unable to work owing to illness or disability
Not in paid employment
Unemployed and looking for work
At home and not looking for paid
Volunteer
Student
Retired
Menopause status (N=4407)
Premenopausal
Perimenopausal
Postmenopausal
Surgical
Unclassifiable b n (%) a
525 (12.1)
1132 (26.1)
728 (16.8)
262 (6.0)
1248 (28.8)
443 (10.2)
2132 (48.8)
1251 (28.6)
299 (6.8)
225 (5.1)
465 (10.6)
84 (1.9)
283 (6.5)
48 (1.1)
13 (0.3)
13
24
(0.3)
(0.5)
1101 (25.0)
1225 (27.8)
955 (21.7)
617 (14.0)
509 (11.5) a Denominator excludes women with missing data b Mirena users; women who began HT whilst still menstruating; those who have had an endometrial ablation; missing data

Table 2.
Frequency of hot flushes (%) by level of bother amongst women who provided information for both frequency of symptom and level of bother (N=1087)
Bother
Not at all/slightly (low bother)
Moderately/quite a bit/extremely (high bother)
Total
Hot flushes
≥ 15 per week (high frequency) 1-7 per week (low frequency) Total
“resilient”
92 (14.6%) 242 (52.7%)
“vulnerable”
334
536 (85.4%)
628 (100%)
217 (47.3%)
459 (100%)
753
1087

Table 3.
Frequency of night sweats (%) by level of bother amongst women who provided information for both frequency of symptom and level of bother (N=1253)
Bother
Not at all/slightly (low bother)
Moderately/quite a bit/extremely (high bother)
Total
Night sweats
≥ 6 per week
(high frequency) 1-5 per week (low frequency) Total
“resilient”
145 (18.3%)
649 (81.7%)
794 (100%)
234 (51.0%)
“vulnerable”
225 (49.0%)
459 (100%)
379
874
1253

Table 4: Factors independently associated with "resilience " (high frequency, low bother) to hot flushes, compared to women with high frequency of hot flushes and high levels of bother (N=628)
Factors investigated
Perceived severity of previous menstrual periods
Not at all to slightly bothered d
Moderately to extremely bothered
Reporting somatic symptoms
0 symptoms d
1 symptom
2 symptoms
3 symptoms
4 symptoms
5 symptoms
Reporting night sweats
No d
Yes
Illness perceptions: Perceived consequences of symptoms for respondent
Low consequences d
Moderate consequences
High consequences
Number resilient: number with high frequency high bother hot flushes
45:158
45:365
32:62
19:137
16:123
10:98
8:63
4:30
25:39
66:491
39:94
37:140
14:276 a
Final model
Adjusted OR (95% CI)
1.00 b,c
0.55 (0.32 to 0.95)
1.00
0.43 (0.21 to 0.90)
0.23 (0.10 to 0.52)
0.32 (0.13 to 0.80)
0.70 (0.25 to 1.94)
0.44 (0.12 to 1.67)
1.00
0.25 (0.12 to 0.50)
1.00
1.01 (0.53 to 1.93)
0.27 (0.12 to 0.61) a Denominator excludes women with missing information b Covariates entered into the forward conditional stepwise logistic regression which were not retained were: number of pregnancies, number of children, educational attainment, BMI, smoking status, alcohol consumption, frequency of exercise, presence of anxiety, presence of depression, SF-12v2 physical summary score, SF-12v2 mental summary score, reporting psychological symptoms, musculoskeletal symptoms, bloating symptoms, sleep difficulties, attitudes towards menopause, current use of complementary alternative medicines, prescription medicines, psychological strategies, and lifestyle changes for symptoms attributed to the menopause. c Model also adjusted for illness representations and symptom management strategies. d Reference group

Table 5: Factors independently associated with “vulnerability " (low frequency, high bother) to hot flushes, compared with women with low frequency of hot flushes and low levels of bother (N=459)
Factors investigated
Number of children
0 d
1
2
3+
Body Mass Index (BMI)
<25 d
25 to 29.99
≥30
Reporting night sweats
No d
Yes
Illness perceptions: Perceived consequences of symptoms for respondent
Low consequences d
Moderate consequences
High consequences a Denominator excludes women with missing information
Number vulnerable: number with low frequency low bother hot flushes a
26:54
38:22
98:102
54:62
77:111
67:68
62:49
32:93
183:147
38:106
70:66
93:48
Final model b,c
Adjusted OR (95% CI)
1.00
4.06 (1.72 to 9.59)
2.02 (1.05 to 3.89)
2.30 (1.10 to 4.85)
1.00
1.39 (0.82 to 2.37)
2.20 (1.25 to 3.88)
1.00
2.91 (1.67 to 5.06)
1.00
2.26 (1.23 to 4.15)
4.01 (2.06 to 7.84) b Covariates entered into the forward conditional stepwise logistic regression which were not retained were: number of pregnancies, educational attainment, smoking status, alcohol consumption, perceived severity of menstrual periods, frequency of exercise, presence of anxiety, presence of depression, SF-12v2 physical summary score, SF-12v2 mental summary score, reporting somatic symptoms, psychological symptoms, musculoskeletal symptoms, bloating symptoms, sleep difficulties, attitudes towards menopause, current use of complementary alternative medicines, prescription medicines, psychological strategies, and lifestyle changes for symptoms attributed to the menopause. c Model also adjusted for illness representations and symptom management strategies. d Reference group

Table 6: Factors independently associated with "resilience " (high frequency, low bother) to night sweats compared to women with high frequency of night sweats and high levels of bother (N=794)
Factors investigated
Smoking status
Neve r d
Current
Ex
Reporting sleep difficulties
No d
Yes
Use of psychological strategies for managing symptoms attributed to the menopause
Not currently using d
Currently using
Illness perceptions: Perceived consequences of symptoms for respondent
Low consequences d
Moderate consequences
High consequences a Denominator excludes women with missing information
Number resilient: number with high frequency high bother night sweats a
84:294
27:176
31:156
36:76
107:569
74:241
71:408
63:110
40:191
31:316
Final model b,c
Adjusted ORs (95% CI)
1.00
0.48 (0.28 to 0.81)
0.64 (0.38 to 1.07)
0.50 (0.30 to 0.83)
1.00
1.00
0.65 (0.42 to 0.99)
1.00
0.38 (0.23 to 0.63)
0.20 (0.11 to 0.37) b Covariates entered into the forward conditional stepwise logistic regression which were not retained were: number of pregnancies, number of children, educational attainment, BMI, alcohol consumption, frequency of exercise, perceived severity of menstrual periods, presence of anxiety, presence of depression, SF-12v2 physical summary score, SF-12v2 mental summary score, reporting somatic symptoms, psychological symptoms, musculoskeletal symptoms, bloating symptoms, hot flushes, attitudes towards menopause, current use of complementary alternative medicines, prescription medicines, and lifestyle changes for symptoms attributed to the menopause. c Model also adjusted for illness representations and symptom management strategies. d Reference group

Table 7: Factors independently associated with "vulnerability" (low frequency, high bother) to night sweats, compared to women with low frequency of night sweats and low levels of bother (N=459)
Factors investigated
Educational attainment
No education/ O levels d
Highers/college qualification
Degree/postgraduate qualification
Perceived severity of previous menstrual periods
Not at all to slightly bothered d
Moderately to extremely bothered
SF-12v2 Physical health summary score
Above the median d
Yes
Below the median
Reporting hot flushes
No d
Number vulnerable: number with low frequency low bother night sweats a
102:79
52:53
68:102
68:104
151:124
85:124
135:107
43:74
179:158
Final model b,c
Adjusted OR (95% CI)
1.00
0.64 (0.36 to 1.48)
0.44 (0.26 to 0.73)
1.00
1.45 (1.01 to 2.32)
1.00
1.56 (1.00 to 2.51)
1.00
1.74 (1.01 to 3.03)
Reporting musculo-skeletal symptoms
0 symptoms
1 symptom
2 symptoms d 23:60
60:53
139:118
1.00
2.85 (1.38 to 5.89)
2.26 (1.33 to 4.50)
Illness perceptions: Perceived consequences of symptoms for respondent
Low consequences d
Moderate consequences
48:85
68:72
1.00
1.74 (0.96 to 3.14)
High consequences 87:49 2.90 (1.48 to 5.66) a Denominator excludes women with missing information b Covariates entered into the forward conditional stepwise logistic regression which were not retained were: number of pregnancies, number of children, BMI, smoking status, alcohol consumption, frequency of exercise, presence of anxiety, presence of depression, SF-12v2 mental summary score, reporting somatic symptoms, psychological symptoms, bloating symptoms, sleep difficulties, attitudes towards menopause, current use of complementary alternative medicines, prescription medicines, psychological strategies, and lifestyle changes for symptoms attributed to the menopause. c Model also adjusted for illness representations and symptom management strategies. d Reference group.