Self-rated health, life satisfaction and personal characteristics of post-menopausal women under estrogen replacement therapy

Maturitas 35 (2000) 71 – 79 www.elsevier.com/locate/maturitas

Self-rated health, life satisfaction and personal characteristics of post-menopausal women under estrogen replacement therapy Margreet S. Duetz *, Thomas Abel, Claudia Meier, Steffen Niemann Unit for Health Research, Departement of Social and Pre6enti6e Medicine, Uni6ersity of Bern, Niesenweg 6, 3012 Bern, Switzerland Received 5 August 1999; accepted 8 February 2000

Abstract Objecti6es. To describe the prevalence of oestrogen replacement thearpy (ERT)-use among post-menopausal women in relation with personal and socio-economic characteristics and to examine the association of ERT-use with self-rated health and selected aspects of life satisfaction. Methods. Population survey data were derived from a cohort study of 511 Bernese women, aged 55–65 years. Data were collected by means of telephone interviews. Overall prevalence of ERT-use, and selected associations with personal and socio-economic characteristics were investigated using descriptive statistical methods and logistic regression. The relations of ERT-use with five self-reported health measures were explored using Spearman’s correlation coefficients. The associations of ERT-use with six dichotomous variables on satisfaction with various aspects of life were tested with chi-square tests in cross tabulations. Results. The overall prevalence of self reported ERT-use was 17.6%. ERT was more prevalent women younger than 61 years than in women in the older age group. Women with a body mass index (BMI) under 25 reported ERT-use significantly more frequently than women with higher BMI (OR =3.16, CI 1.87 – 5.34). ERT-use was more prevalent in women with relatively high education: OR =2.01, CI 1.18-4.00. The self-reported health measures and the satisfaction items were not significantly associated with ERT-use. Conclusions. ERT-use among post-menopausal women was found to be associated with higher educational level and lower BMI. ERT-users did not report better health or life-satisfaction. © 2000 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Post menopausal women; Socio-ecnomic; Oestrogen replacement thearpy (ERT)

1. Introduction Peri- and post-menopausal women are frequently advised to undertake oestrogen replace* Corresponding author. Tel.: +41-31-6313512; fax: + 4131-6313520. E-mail address: [email protected] (M.S. Duetz)

ment therapy (ERT). The possible benefits of ERT are basically of two dimensions; direct effects and preventive effects. Medical reasons for ERT-use relate to both dimensions. With regard to the direct effects, ERT is used to treat symptoms which are caused by the process of hormonal change. Some of these symp-

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toms are most prevalent in the years of perimenopause, such as hot flushes and mood fluctuations, whereas other symptoms may as well occur in the post-menopausal life span, for instance vaginal dryness, weight gain and altered patterns of body fat distribution [1,2]. The direct effects of ERT-use are believed to result in a better quality of life. In several studies, the influence on well-being has been confirmed with regard to women that suffer menopausal symptoms [3 – 5]. Yet, other authors find no improvement of quality of life under ERT [6]. The second type of benefits of ERT are of a preventive character. The use of ERT was found to be associated with a reduced risk of coronary heart disease including direct effects on mortality [7]. They also tend to comply better to various other prevention measures than non-users do, which may influence mortality further [8]. ERT has shown to be ineffective for the purpose of preventing cardiac events like myocardial infarction and death due to coronary heart disease, in women with established CHD [9]. The risk of osteoporosis in old age is reduced in long-term ERT-users, as well as the risk of fractures due to osteoporosis [10]. Recently, there is preliminary evidence that ERT might also influence the risk of Alzheimer disease, as it would prevent the occurrence of this disease to some extent, and slow down the process of loosing cognitive functions, once the disease is manifest [11,12]. The cited studies, however, are subject to important methodological criticism [13]. In spite of those potential benefits, there are also several problems linked to ERT. Of serious concern are the indications that ERT increases the risk of breast cancer [14 – 16]. In these studies, increase in incidence of breast cancer in ERT-users as compared to non-users was in the magnitude of 10 – 40%, depending, among other factors, on the ERT-dosage, the combination with other agents and the duration of use. However, the risk of dying from breast cancer seems not to be increased for women using ERT [17]. The risk of endometrium cancer is also increased in postmenopausal women using hormonal substitution, although the addition of

gestagens in the therapy reduces the increase of this risk [15]. The individual compliance to ERT is a further problem issue, as it is often poor [18]. Some oestrogen replacement therapies are disrupted early because of harmless, but unwelcome side affects [19]. Also, many women disrupt the ERT only after a few months for motivational reasons [20]. They perceive themselves healthy in spite of the menopause, and may therefore be reluctant to comply to the therapy, or if they do experience symptoms of menopause, they accept them as a sign of a natural stage of life. This attitude coincides with the viewpoint from feminist scientists, that also refer to the menopause as a natural process and plead for a broader view on menopause, applying a psycho-social understanding of this life stage [21–23]. Thus, the decision to whether or not to subscribe or submit to ERT is a complex one and might be strongly influenced by individual characteristics of both physician and patient, in particular, knowledge on medical benefits and risks, attitudes towards menopause and the ageing process, the medical status of the patient regarding risk factors for cardiovascular disease and osteoporosis, her family history of breast cancer and her subjective judgement of the seriousness of her symptoms of (peri-)menopause [24]. Furthermore, the patient and her physician may be influenced by the images of ERT as presented by advertisements, which generally show joyful, attractive and youthful women as typical ERT-users [25,26]. This brief review demonstrates the complexity of the issue of ERT and the variety of reasons and motives for its use. However, until today knowledge about correlates or determinants of ERT-use is still scarce. On this background, the research question addressed in the present study concerns the shortterm effects of ERT on subjective well being. Concretely, we will investigate whether women who are currently using ERT report better health and higher degrees of life satisfaction. The issue of ERT and quality of life has been studied previously, yet those studies were generally based on restricted samples of women with serious menopausal symptoms. ERT however, is also ex-

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pected to result in improvement of well-being in average post-menopausal women, in whom mild menopausal symptoms are very common [27,28]. Therefore, we are particularly interested in the relations between health and satisfaction in normal populations, as represented by the respondents of a general population survey. To answer this question, we will analyse the associations of ERT-use and self-reported health variables and satisfaction with various aspects of life. Prior to investigate the main research topics, we will describe the prevalence of self-reported ERTuse in the sample and differentiate this prevalence according to indicators of social class and behavioural characteristics. We expect to find, in accord with previous studies, higher probabilities of current ERT-use in women from middle and high social classes and greater economic independence [29 – 31]. Also, the type of health insurance may influence the prevalence of ERT-use [32]. Studies on ERT-use and health behaviour have demonstrated that ERT-users tend not to smoke and have low body weight. This pattern indicates a tendency of health-related behaviours and characteristics to cluster among certain groups or individuals [7,33,34]. Therefore we test for relationships of ERT with smoking and body weight.

2. Material and methods

2.1. Data Data from a survey on health related lifestyles were used. The survey was carried out in three waves from 1996 to 1998. In 1996, 1119 (64.4%) of the 1913 sampled men and women participated, 923 (82.9%) of whom participated also in the second wave. In this paper, only data of the second wave were used [35]. The data were gathered using CATI, a computer assisted telephone interview technique. This technique was handled according to the recommendations of the US American centre of Disease Control, which has long-standing experience with telephone interviews on health-related subjects [36]. In the Swiss context, very few problems concerning the attain-

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ability of the responders occur, because over 99% of the Swiss households are connected to the telephone network. Apart from the establishment of ERT-use, measures were taken of selected aspects of the health status, of demographic and socio-economic factors and of psycho-social resources.

2.2. Measures 2.2.1. ERT-use Respondents were asked, ‘Do you regularly take sex hormones, estrogens, the pill?’. In the post-menopausal age group of 56–66 year, sexhormone therapies other than ERT are extremely rare [37]. Moreover, none of the subjects reported any gynaecologic or endocrinologic disease, that would give rise to a therapeutic goal other than post-menopausal estrogen replacement. Accordingly, a positive response was classified as a sufficiently valid indicator for ERT-use. 2.2.2. Characteristics of ERT-users Age of respondents in the BLP ranged from 56 to 66. For the present analysis, age was recoded into a dichotomous variable: younger than 60 years and aged 60 and over. Social class was measured by items on education, income and employment status. Education was originally reported in seven categories and thereafter recoded in two categories; secondary school or less and higher degrees, including vocational training. The income variable was based on the total household income, which was recorded in categories per 1000 Swiss Francs. The size of the household was adjusted for by dividing the total income by the number of household members, whereas the first member counted as one unit, and any subsequent member as 0.5 unit. The cut point for dichotomising was chosen in a manner that defines material deprivation rather than wealth: one third of women reported an income under the cut point of 3000 SFr. The dichotomised indicator of health insurance status separates women with third class insurance, which is the least expensive insurance class in Switzerland, from the second and first class insured women.

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Employment status was dichotomised in a group of women with paid jobs and a group without, regardless of possible part-time occupation. Information on parity (motherhood) is of interest because of the previous contradictory findings on the subject of ERT-use and parity [29,38]. In the present analysis, a dichotomous variable was constructed, that distinguished women with one or more children from women without children. Two indicators of health behaviour were included. Body mass index (BMI) was computed in its standardised form as body height in meters divided by square body weight in kilos. The cut point, 25 kg/m2, was chosen between normal weight and overweight. Smoking status separated current smokers from non-smokers.

2.2.3. Health measures Self-rated health was assessed by the following question: ‘How is your health at the present time?’ Five answer categories ranged from ‘very good’, (5 points) and ‘very bad’ (1 point). Self-rated health is a frequently used health measure in population surveys. Its validity and reliability are repeatedly substantiated, and despite its subjective character, it is known to be a strong predictor for both future disability and longevity [39 – 41]. In order to assess the physical fitness, we used a 12-item questionnaire developed by Bo¨s et al. [42]. This scale measures physical fitness in four dimensions: muscle strength, endurance, agility and coordination. Each of those dimensions is covered by three questions. The endscore consisted of the mean score at the 12 items and had a maximum of 5 points. In order to measure restrictions due to disease, respondents were asked ‘Apart from minor illnesses, how strongly have you been limited in the performance of your daily tasks, e.g. house work, job or leisure time in the last twelve months because of disease?’ Answers were coded on a 5 point scale ranging from ‘very strongly’ to ‘not at all’. A dichotomous indicator for medication intake was based on responses to the question: ‘Do you regularly take any medications?’ ERT-users, that reported regular intake of medicaments other

than ERT, were assigned to the group of women with regular medication intake. Finally, utilising a list of the leading health problems, subjects were asked to report on the prevalence in the past 24 months of a number of diseases: diabetes, hypertension, chronic pulmonary disease, angina pectoris or myocardial infarction and cancer. The 12-months prevalence of osteoporosis, arthrosis and migraine was also recorded. Other serious diagnoses could be reported to an additional open answer question. A sum-score measuring the number of reported diagnoses was constructed, ranging from 0 to 9 points.

2.2.4. Satisfaction 6ariables Satisfaction with life in general, sometimes differentiated along certain aspects of life, is used as an indicator for well-being in specific areas of life, both in population surveys and in clinical studies [43]. In other to establish life satisfaction, we used an instrument which, was developed, validated and employed in the German language area [44,45]. Respondents were asked how satisfied they were with the following six aspects of their life: marriage or partnership, leisure time, job, family life, sexuality and life in general. There were two answer categories; rather satisfied or rather unsatisfied.

2.3. Statistical procedures The prevalence of ERT-use in association with socio-demographic and personal characteristics were examined using a logistic regression, in which the explaining variables are introduced in one single step (forced entry). The corresponding results are shown in Table 1. Associations between current ERT-use and five self-reported health variables were analysed using Spearman’s correlation coefficients. Respective results are shown in Table 2. The associations of ERT-use with six dichotomous satisfaction items were analysed using cross-tabs and chi-square tests and are presented in Table 3.

M.S. Duetz et al. / Maturitas 35 (2000) 71–79 Table 1 Odds ratios of current ERT-use related to socio-demographic and behavioural characteristics, based on logistic regressiona All explanatory variables in one equation

Odds ratio (95% CI)

Age B= 60 years (ref: \60 years)

1.73 (1.00–2.99)

Income \= 3000 Sfr./month (ref: B3000 Sfr./month)

1.32 (0.66–2.67)

Education Vocational training and higher (ref: primary or secondary school)

2.01 (1.18–4.00)

Insurance status First and second class, (ref: third class) Occupational status With paid work, (ref: without paid work)

1.13 (0.80–1.61)

The association of ERT-use with educational level proved to be statistically significant. ERT use was not more, or less, prevalent among women with paid work and among women who have had at least one child. With regard to the behavioural characteristics, no difference in prevalence of any importance was found between smokers and nonsmokers. A BMI under 25, however, was significantly associated with the use of ERT (OR= 3.16, CI 1.87–5.34). In Table 2, correlation coefficients of current ERT-use and self-reported health variables are displayed. ERT-use was not significantly associated with any of the health variables. Similarly, associations of ERT-use with life satisfaction (Table 3) were not significant.

0.61 (0.34–1.04)

4. Discussion

Smoking status Current smoker, (ref: no smoker)

0.67 (0.35–1.28)

Parity No children, (ref: one child or more)

1.12 (0.62–2.04)

BMI B25 kg/m2 (ref: \= 25 kg/m2)

3.16 (1.87–5.34)

a

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(N = 511; 90 ERT-users, 421 non-users).

3. Results Among the 511 post-menopausal women in our sample, 90 (17.6%) reported current ERT-use. In a Swiss nation wide survey, that was carried out in the same year, 114 (19.7%) of 580 women of the same age group in the German speaking regions of Switzerland reported post-menopausal hormonal substitution therapy [46]. These percentages are of similar magnitude, which supports the validity of ERT reports in our sample. Some of the personal characteristics, controlled for by the remaining characteristics, appeared to influence the prevalence of ERT use (Table 1). In our sample, women in the age group of 56 – 60 years were more likely to use ERT than women aged 61–66 years. Women of middle and high social classes, operationalised by income, education and insurance status, also reported ERT-use more frequently than women with a small income.

In our sample, prevalence of ERT-use varied slightly depending on the personal characteristics of the respondents. We found a higher prevalence of ERT-use among women aged up to 60 years as compared to women over 60. This is possibly due both to the prevalence of symptoms associated with menopause in the younger age group, and to the lack of long-term compliance [47,48]. ERT-use was more prevalent in relatively highly educated women, probably because education facilitates the understanding and implementation of health messages. This finding is in accordance with both our hypothesis and findings of other authors [29–31]. As education is also associated with other beneficial health behaviour, such as participation to screening programs, the high level of education may provide a bias in studies on the effects of ERT-use [49]. Women with a BMI under 25 kg/m2 used ERT significantly more frequently compared to women with a higher body mass index. This association was also found in earlier studies [50]. The reasons for this relationship are at least twofold. Firstly, a moderate or low body mass is connected to active health promoting attitudes. The use of ERT coincides with the tendency of these women to influence their well-being actively, for instance with physical exercise and healthy nutritional habits.

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Estrogen replacement therapy Self-rated (ERT) health Estrogen replacement therapy 1.000 (ERT) Self-rated health −0.007 Fitness 0.008 Restrictions due to disease 0.018 Medication intake 0.077 No. of diseases .075 a

Spearman’s coefficients (N= 511). * Significance level: PB0.01, (two-tailed).

1.000 0.483* −0.469* 0.307* −0.423*

Fitness

1.000 −0.438* −0.309* −0.445*

Restrictions due to disease

Utilisation of medical services

1.000 0.372* 0.377*

1.000 0.367*

No. of diseases

1.000

M.S. Duetz et al. / Maturitas 35 (2000) 71–79

Table 2 Correlations of current ERT-use with self-reported health variablesa

M.S. Duetz et al. / Maturitas 35 (2000) 71–79

Secondly, the risk of osteoporosis is also associated with low body mass, and this risk is thought to be reduced by ERT-use, so that women with low body weight have a stronger indication, in this respect, to use ERT. Hence, normal and low weight women may both be more inclined, and more often advised to submit to ERT [51]. The positive effects of the ERT-use on health can be easily overestimated because of these associations. In studies on ERT and prevention of cardiovascular disease, the association of low BMI and ERTuse presents such a selection bias in particular, as the absence of obesity in itself reduces the risk of coronary heart disease [52]. To answer the question whether ERT-use among post-menopausal women results in higher well-being, the correlation of ERT-use with selfreported health variables and the associations of ERT-use with satisfaction were studied. None of the health indicators showed a significant correlation with ERT-use. Also, no significant association between life satisfaction and the use of ERT was found, neither with satisfaction with life in general, nor with specific life areas. Particularly noteworthy appears the absence of any relation with satisfaction with sexuality, as ERT is thought to diminish vaginal dryness and other sexual dysfunctions during peri-menopause. As all data were gathered using telephone interviews, there was no direct control over the validity of the statements. However, previous analyses with the data set delivered solid results, that remained stable in the run of the three measurements [35]. The inner associations of the health parameter proved to be strong and consistent [53].

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With regard to the satisfaction parameters, we relied on the validation analyses of the measuring instrument by other authors [44]. The present findings suggest no significant effects on well-being. These findings must be interpreted behind the background of a cross-sectional study design. The study design allows for division of the sample in ERT-users and non-users, but does not provide knowledge on health states prior to ERT-use, and might thus be subject to membership bias [54]. We do not know, if the ERTusers were in worse health states than the non-users in a period of time preceding our study, which could actually be the reason for ERT-use. The present findings do show, however, that to a given point in time, in a sample of postmenopausal women in the general population, no difference in self-reported health and satisfaction between ERT-users and non-users is apparent. In conclusion, the present findings of a cross sectional population study indicate no association of ERT-use with self reported health and life satisfaction. ERT-users, though, show a different profile of socio-demographic and health behaviour characteristics than non-users do. These findings may help to build a differentiated and actual image of ERT-users, whose typical characteristics, especially their relatively low body weight and high level of education, may confound the results of studies on effects of ERT-use. For a definite answer to the question if ERT-use improves the level of well-being in a general population, randomised control study or a long term population survey would be required.

Table 3 Number and percentage ‘rather satisfied’ ERT users versus non-usersa Aspect of life

Satisfied ERT- users n/%

Satisfied non-users n/%

N

Partnership Leisure time Job Family life Sexuality Life in general

69/92.0 86/95.6 83/95.4 82/95.3 61/70.9 87/96.7

334/92.5 385/91.4 385/94.4 397/97.3 301/75.8 401/95.7

436 511 495 494 483 509

a

P\0.05 in every equation.

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