Use of complementary and alternative medicines for menopausal symptoms in Australian women aged 40–65 years

For many of the 3.7 million women aged 40 to 65 years in Australia, who account for 14% of the population, menopause presents a health challenge. Use of oestrogen for the relief of menopausal vasomotor symptoms (VMS) (eg, hot flushes, night sweats) was common until 2002, when concerns about the safety of menopausal hormone therapy (MHT) arising from a Women’s Health Initiative study1 triggered a dramatic decline in the prescription of MHT. Concurrently, the use of complementary and alternative medicine (CAM) has grown considerably,2 with one Australian study reporting that most women presenting to a menopause clinic had used CAMs for their menopausal symptoms.3 However, there is insufficient evidence to support the use of CAMs that are most visibly promoted for managing VMS, such as black cohosh and phytoestrogens.4,5 Women at midlife are also likely to be taking other CAMs to manage other menopausal symptoms.

The current prevalence of the use of CAMs specifically for menopausal symptoms in Australia is not known. We aimed to investigate the prevalence of CAM use and consultations with CAM practitioners for menopausal symptoms by Australian women at midlife.

Methods

Study participants

Recruitment to this study has been reported in detail elsewhere.6 In brief, between October 2013 and March 2014, women aged 40–65 years listed on a large, representative, national, continually refreshed database based on the electoral roll were randomly invited by telephone to participate in a survey about the health of women at midlife. The only exclusion criterion was inability to complete a questionnaire in English. A study questionnaire with a reply-paid envelope was posted to each woman who gave verbal consent. Return of a completed questionnaire was accepted as written informed consent. The Monash University Human Research Ethics Committee approved the study. We used the STROBE guidelines to report the study findings.

Questionnaire

The questionnaire provided women with a specific list of CAMs that are commonly used for relieving menopausal symptoms and asked them to indicate which of these they had used in the past 4 weeks. For our analyses, we grouped these CAMS according to whether they are commonly used for VMS (eg, black cohosh, phytoestrogen products), sexual symptoms (eg, horny goat weed, maca) or other menopausal symptoms such as joint pain, sleep disturbance and mood (eg, fish or krill oil, glucosamine).

The women were also asked about their current use of systemic MHT, including prescription oestrogen, oestrogen plus progestogen (including the oral contraceptive pill and compounded hormones) and tibolone.

The questionnaire further provided women with a list of CAM practitioners and asked them to indicate which, if any, they had consulted for menopausal symptoms in the past 12 months. The practitioner list comprised: chiropractor, naturopath, acupuncturist, herbalist, Chinese medicine practitioner, homeopath, osteopath, spiritual healer, kinesiologist, aromatherapist, iridologist and Ayurveda therapist.

Assessment of menopausal status

Women were classified as premenopausal, perimenopausal or postmenopausal using published algorithms7 derived from the Stages of Reproductive Aging Workshop + 10 criteria.8 Classification was based on age, history of bilateral surgical menopause, menstrual bleeding, VMS and hysterectomy. Use of systemic hormonal contraception or MHT was also taken into account. We further divided the postmenopausal group into women aged 40 to < 55 years, 55 to < 60 years, and 60–65 years.

Assessment of menopausal symptoms

We assessed menopausal symptoms using the Menopause-Specific Quality of Life (MENQOL) questionnaire, a validated self-administered instrument comprising four symptom domains: vasomotor, physical, psychological and sexual.9 Women reported if they had experienced each symptom in the past 4 weeks (yes/no) and the extent to which they were bothered by it (ranging from 0 [no bother] to 6 [extreme bother]). Each individual question had a range of 1–8, with 1 being no symptoms. The symptoms were rated on a seven-point Likert scale, and women who ranked their degree of bother as more than the midpoint of the item (score, > 5–8) were considered to have moderate–severe symptoms.

Sample size

We calculated that our required sample size was 2000, based on the primary study outcome of moderate–severe VMS, with a 95% confidence interval of ± 2% around a percentage prevalence estimate of 30%. We purposefully sampled women so that the age distribution of our sample population mimicked the age distribution of Australian women aged 40–65 years in 2011.6

Statistical analyses

The characteristics of study participants, use of CAMs and consultations with CAM practitioners are presented as frequencies and percentages.

We performed three separate logistic regression analyses, where the outcome variables were CAM use for VMS, CAM use for other symptoms, and consultations with CAM practitioners. Too few women were using a CAM intended for sexual function to justify separate regression modelling for this outcome. Factors associated with CAM use for VMS and other symptoms in bivariate analysis at P < 0.05 were included in the final regression models. All tests were two-sided and the a level was 0.05 for all statistical tests. We performed all analyses using Stata version 12.0 (StataCorp).

Results

Of 5850 women who were contacted, 2911 agreed to participate, and 2023 subsequently returned completed questionnaires. Three completed questionnaires were from women outside the study age range, so the final sample consisted of 2020 women (response rate, 34.53%). Most women were postmenopausal (1109; 54.90%), resided in metropolitan areas and were born in Australia (Box 1).

Current use of MHT was reported by 12.18% of the women; 13.24% had undergone hysterectomy without oophorectomy, and 5.45% had surgical menopause (Box 1). Among women not using MHT, 52.06% reported having VMS, 86.69% had psychological symptoms and 97.40% had physical symptoms. Among women not using MHT or vaginal oestrogen, 57.18% reported sexual symptoms.

Of women reporting any symptoms in the MENQOL domains, the symptoms were reported as moderate–severe by 12.80% (221/1727) for VMS, 19.86% (332/1672) for sexual symptoms, 15.39% (266/1728) for physical symptoms, and 16.15% (279/1728) for psychological symptoms.

CAM use for menopausal symptoms

The prevalence of use of at least one CAM for any menopausal symptoms was 39.16% (Box 2). Of the 2020 women, 267 (13.22%) reported using CAMs for VMS, with the most frequent use reported by perimenopausal women (18.85%; 72/382) (Appendix 1). Phytoestrogens were the most commonly used CAM for VMS (6.29%), followed by evening primrose oil (3.91%), ginseng (1.73%) and black cohosh (1.49%). Nearly half the women who used MHT had also used a CAM (112/246; 45.53%), including 34 women (13.82%) who had used a CAM for VMS. Only 16 women (0.79%) used a CAM for sexual symptoms.

Of the 2020 women, 651 (32.23%) used at least one CAM for other symptoms, with the most frequent use by postmenopausal women aged 60–65 years (Appendix 1). Overall, fish or krill oil was most commonly used for other symptoms (24.36%), followed by glucosamine (12.13%) (Box 2). Of the 358 women aged 60–65 years, 128 (35.75%) reported taking a fish oil supplement and 61 (17.04%) were taking glucosamine.

Factors associated with CAM use for menopausal symptoms

Compared with premenopausal women, perimenopausal and early postmenopausal women were significantly more likely to use any CAM for VMS (Box 3).

The likelihood of CAM use for other symptoms was significantly greater for perimenopausal and all postmenopausal women than for premenopausal women. Women residing in non-metropolitan areas were less likely than metropolitan residents to use a CAM for other symptoms. Experiencing psychological or physical symptoms was not associated with the use of CAMs for other symptoms (Box 3).

Consultations with CAM practitioners

Overall, 8.33% of women (168/2017) reported having at least one consultation with a CAM practitioner for menopausal symptoms in the past 12 months (Appendix 2). The practitioners most frequently consulted were chiropractors (2.78%), naturopaths (2.68%) and acupuncturists (1.98%). The women most likely to have consulted a CAM practitioner were those experiencing VMS (adjusted odds ratio, 1.80; 95% CI, 1.20–2.71) and those who were educated beyond high school (adjusted odds ratio, 1.56; 95% CI, 1.07–2.29) (Appendix 3).

Discussion

In this large, representative, cross-sectional sample of Australian women aged 40–65 years, we found that 13.22% had used at least one CAM for VMS, similar to the proportion of women of this age who were using MHT. More than one in 10 women using MHT also used a CAM for VMS. We also found that a third of study participants reported the use of CAMs for other symptoms.

CAM use for VMS was highest in perimenopausal and early postmenopausal women, with the prevalence in these groups close to one in five. These women, compared with premenopausal and older postmenopausal women, also reported the most severe menopausal symptoms.6

Applying our findings to the 3.7 million Australian women aged 40–65 years would mean that 490 000 women had used CAMs for VMS in the past month, and 303 000 would have consulted a CAM practitioner for menopausal symptoms in the past year. In addition, 883 000 women would have taken fish or krill oil and 438 000 would have taken glucosamine in the past month.

Phytoestrogens, the most commonly used CAMs for VMS, have not been shown to be effective for treating VMS, either as food supplements or as concentrated tablets.5 Evening primrose oil, black cohosh and ginseng, the other commonly used CAMs for VMS, overall appear to be no more effective than placebo.10,11 Importantly, CAMs such as ginseng will have varying effects according to the species used and potency and bioavailability of the formulation.12,13 The effects are not always desirable, with the known side effects of ginseng including hypertension, diarrhoea, sleeplessness, mastalgia with diffuse mammary nodularity, skin eruptions and vaginal bleeding.12,13 Given the lack of evidence regarding benefit of CAMs for alleviating VMS, as well as the potential adverse effects and their high cost, the continuing use of these CAMs for this purpose cannot be supported.

We found that the prevalence of use of CAMs for other symptoms was high among older Australian women, with fish or krill oil and glucosamine the most commonly used. Fish oil is promoted for a wide range of conditions, most notably for preventing cardiovascular disease.14 Fish oil inhibits platelet aggregation and has been associated with a modest increase in bleeding time,15 but there has been controversy regarding its efficacy in preventing cardiovascular disease.16 Glucosamine, taken alone or in combination with other supplements such as chondroitin, is most commonly used for arthralgia. However, the United Kingdom’s National Institute for Health and Care Excellence does not recommend the use of glucosamine or chondroitin for the management of osteoarthritis.17 Recent studies linking glucosamine to ß-cell dysfunction and decreased insulin secretion18 raise concern, particularly in the context of high usage of this CAM by older people.

The higher prevalence of CAM use for symptoms other than VMS among women residing in metropolitan rather than non-metropolitan areas may reflect availability and income differentials between these regions. Others have found that women with poor self-reported health or chronic diseases are more likely than their healthier counterparts to take supplements.19 In our study, women with psychological and physical symptoms of menopause were not more likely to take a CAM. This could be because such a high proportion of women reported psychological and physical symptoms, and because of the widespread indiscriminate use of fish oil and glucosamine in the community.

There is evidence that CAM use is supported by health practitioners. A national survey found that about a third of Australian general practitioners self-identified as practising complementary therapy.20 It is a cause for concern that a sizeable proportion of Australian practitioners are recommending ineffective therapies.

We found that the proportion of women consulting a CAM practitioner for menopausal symptoms was threefold lower than that reported by menopause clinic respondents (25.2%) in Australia.3 This difference is likely because our study used a community-based, rather than clinic-based, sample. Our finding that chiropractors and naturopaths were the most commonly consulted CAM practitioners is consistent with a previous community-based survey.14

Our finding of a higher prevalence of CAM consultations among women educated beyond high school is similar to that in another study, which found that better educated women were more likely to consult CAM practitioners.21 This may be a function of greater uptake of private health insurance (PHI) among educated women. Higher educational achievement, as a proxy measure of higher income, has been found to be associated with greater uptake of PHI.22 Furthermore, people with PHI have been found to be significantly more likely than those without PHI to see CAM practitioners in Australia.23 Many PHI funds provide cover for consulting CAM practitioners, such as homeopaths and naturopaths. However, these rebates are not yet underpinned by credible evidence of clinical efficacy, cost-effectiveness, safety and quality.24

In contrast with consulting CAM practitioners, we found that use of CAM products was not associated with education level. This may be because of the lower cost burden of CAM products relative to consultations with CAM practitioners, and greater acceptance of use of CAM products in the community.14,25

This is the first Australian community-based study of use of CAMs and CAM practitioners specifically for menopausal symptoms. Previous studies have reported overall use of CAMs by Australian women at midlife, with prevalence ranging from 48.5% to 82.5%,2,3,14 higher than our finding of 39.16%. The higher prevalence in these studies is due to the inclusion of a broader range of CAM therapies, such as change in diet, exercise and use of vitamins. A recent Australian study reporting a higher rate of consultations with CAM practitioners was not menopause-specific and included practitioners such as massage therapists.26

An important strength of our study is the use of national random recruitment of a representative sample of women, rather than convenience sampling. Although we were unable to compare the demographics of respondents and non-respondents, comparison with Australian 2011 census data has shown that our sample is nationally representative of women in this age range in terms of basic demographic characteristics, including metropolitan location.27

A further strength of our study is that participants were provided with a comprehensive list of the CAMs specifically used for menopausal symptoms.

A potential limitation is that proficiency in English was required to complete the study questionnaire. This is unlikely to have affected the representativeness of our sample, as English literacy in Australian women exceeds 96%.6 Our response rate of 34.53% indicates that selection pressures were operative, but this rate is high compared with rates recently reported for similar studies.28

In conclusion, a significant proportion of Australian perimenopausal and early postmenopausal women are using CAMs that are known to be ineffective for managing VMS. Furthermore, the use of fish oil and glucosamine supplements is common in the community, yet the efficacy and long-term safety of these supplements are yet to be established. Health care providers need to actively guide women in the management of VMS and other menopausal symptoms.