  |
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Journal of the New Zealand Medical Association,
26-November-2004, Vol 117 No 1206
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Changes in the use of Hormone Replacement Therapy in New
Zealand following the publication of the Women’s Health Initiative
Trial
Irma Bilgrami, Katy Blower, Jason Feng, Georgia Stefanko,
Eugene Tan
The first results of the Women's Health Initiative (WHI)
Trial were published in July 2002.1 This was a
randomised controlled trial of combined hormone replacement therapy (HRT) and
placebo. The results disproved a protective effect of HRT on coronary heart
disease, which had been seen in observational
studies.2 The trial also showed that there
were, overall, more adverse than beneficial outcomes with long-term use of HRT.
In September 2002, the Ministry of Health issued advice that
(in most circumstances) combined-HRT should not be used for longer than 3 to 4
years; and use for shorter periods should be considered ‘only where
menopausal symptoms are disruptive to the quality of life of the
woman’.3
A national survey in 1997 showed that 20% of women aged 45
to 64 years were using HRT.4 We undertook a
further national survey to find out what women had heard about the WHI results,
whether they had changed their use of HRT in response to these results, and (for
women who had chosen to stop) the effects, if any, of discontinuation.
MethodsA population-based survey was
conducted in December 2002. A sample of 500 women aged 45 to 64 years was
randomly selected from the electoral rolls. A questionnaire was sent to each
participant.
This questionnaire was based on the earlier surveys by
North and Sharples in 1991 and 1997.4
Information was sought on use of HRT (in the form of pills, patches, or
implants) at any time in June 2002, and at the time of interview. Reasons for
starting and stopping HRT-use were sought, and questions were asked about
knowledge of risks and benefits of HRT-use.
To ensure a high response rate, women who did not
return the questionnaire within 10 days were followed up by phone. To ensure
consistency we compiled a set format of questions and responses to be used for
each follow-up call. Women who were unwilling to complete the whole
questionnaire were asked if they could answer two questions about whether they
were taking HRT in June 2002 and whether they were currently taking it. Ethical
approval was given by the University of Otago Ethics Committee, under Category
B. Chi squared tests or Fisher’s exact tests were used to compare the
proportions between groups of interest.
ResultsQuestionnaires were sent to 500
women. Of these, 18 were returned to sender or the respondent was of male
gender. Exactly 298 completed questionnaires were returned and a further 20
responses were obtained by phone. Thus, the total response rate was 66%
(318/482).
The mean age of the women was 54 years. The majority (92%)
of women questioned described their ethnicity as European while 4% were Maori.
Overall, 77% described their health as either ‘good’ or ‘very
good’, and 45% had a tertiary or vocational level of education.
Table 1. Prevalence of use of HRT by women aged 45 to
64 by time period
As seen in Table 1, during June 2002—before the
results of the WHI trial were published—15% of women were using HRT in
comparison to 20% in 1997.4 Following the
publication of the WHI trial, only 11% of women were taking HRT in December 2002
(p=0.15). Thus 15 women (approximately one-third of women who had been HRT users
in June 2002) had discontinued HRT. A further 10 women (21% of users) were
tapering their dose with the view to stopping HRT at the time of answering the
questionnaire. No significant difference was found between those who stopped,
and those who continued HRT with regards to age, initial prescriber of HRT or
educational level.
Symptomatic relief was the main indication for use, both
before and after publication of the WHI study, with vasomotor symptom control
being the most common reason for use as stated by 62% of users in June 2002 and
44% of users in December 2002. At both time periods, 40% of women took HRT for
osteoporosis prevention. Only one woman in both June 2002 (2%) and December 2002
(3%) took HRT for prevention of coronary artery disease.
Table 2. Type of HRT used according to time period of
current use*
HRT=Hormone Replacement
Therapy; *The type of preparation was not known for 4 users in June 2002 and
5 users in December 2002.
Of those women taking HRT in June 2002, 58% had had a
hysterectomy compared with 64% of women taking HRT in December 2002. Both before
and after June 2002, as shown in Table 2, use of oestrogen-only HRT was more
common than use of combined oestrogen and progestogen preparations. Stopping was
more common among women taking combined preparations. Among combined users, 9/18
(50%) stopped, while among oestrogen-alone users only 4/26 (15%) stopped
(p=0.07).
Amongst the group who stopped HRT after June 2002, two (13%)
users no longer had the problems they initially took it for, three (20%) stopped
because of side-effects, and eight (53%) stopped directly in response to having
heard recent research findings. Finally, two (3%) stopped HRT for other reasons.
With regard to method of stopping, 11 (73% of all women who stopped taking HRT)
talked it over with their health professional, 11 (73%) stopped it immediately,
and 4 women gradually reduced their dose over time.
In total, 9 (64%) of the women who stopped HRT after June
experienced symptoms, of whom 7 had stopped immediately while 2 had tapered
their doses before stopping. Hot flashes was the most common symptom
experienced.
Responses about sources of information were received from
287 women. The majority of women, 84% (242/287), had heard information about HRT
since June 2002. There was no association between level of education and having
heard information. Most women had heard this information through the media, with
television or radio coverage reaching 68% of women. Only 19% of women noted a
doctor to be a main source of information, and just 4% gained information from
the internet. Overall, 58% of women stated their viewpoint had been influenced
by what they had heard.
Women were asked to give their opinion about a number of
statements on HRT use, as shown in Table 3. The responses of women who had never
taken HRT were compared against those women who had taken HRT at some time.
There were statistically significant differences between the two groups. Those
who had ever used HRT had much more favourable views about the effectiveness of
HRT for treatment of menopausal symptoms and were much less likely to regard the
menopause as a natural process for which they preferred natural
remedies.
Table 3. Respondents’ opinions about HRT use
according to their use of HRT: percentage of respondents who agree or strongly
agree
HRT= Hormone Replacement
Therapy; *Statistically significant difference between ever users and never
users: p<0.001.
When the responses of women who had stopped HRT since the
results of the WHI study were compared to those of current users, the only
statistically significant difference (p=0.008) was that the current users were
more comfortable taking HRT (73%) as opposed to those who stopped (45%).
A comparison was made between women who had recently heard
new information about HRT and women who had not. Again, the only statistically
significant difference (p=0.026) was that 70% of women who had heard the
information would not feel comfortable taking HRT, whereas only 45% of women who
hadn’t heard any new information felt this way.
Women were asked about the harms and benefits of HRT in
relation to specific outcomes (Table 4). Most women understood the relationship
between HRT and both breast cancer and osteoporosis, while only 45% of
respondents correctly believed HRT to increase the risk or have no effect upon
coronary heart disease. Only 9% of women thought HRT reduced the risk of
colorectal cancer.
Women who recalled hearing some recent information on HRT
were (overall) better informed about the risk of breast cancer, coronary heart
disease, and stroke compared with those women who had not heard recent HRT
information, and they were also more likely to understand the protective effect
of HRT on osteoporosis. In spite of this, 34% of women who had heard information
were unsure as to the effect of HRT on the risk of coronary heart disease. No
significant difference was found regarding knowledge on colorectal cancer and
venous thromboembolism.
Table 4. Proportion of women reporting correct
understanding of harms and benefits of HRT according to whether women had heard
about the WHI results (the correct understanding is based on the WHI
results1 and a subsequent
meta-analysis9)
Statistically significant
difference between those who had heard information and those who had not:
*p<0.05, †p<0.01, ‡p<0.001
DiscussionMost women interviewed had heard
about the findings of the WHI trial, and those who had heard the findings were
more likely to correctly state the benefits and harms of long-term use of HRT.
In June 2002, before the results were published, 15% of women were using HRT but
by December, this had dropped to 11%. Of those who stopped completely, 53% did
so in direct response to the research findings. Recurrence of symptoms was
experienced by 64% of women who stopped HRT. We do not know if the women who saw
a health professional regarding HRT-use were patient- or health-professional
initiated, or even whether it was just an opportunistic discussion that took
place on a routine visit.
This study used a random sample from the electoral roll and
achieved, with phone follow-up, a reasonable response rate of 66%. It was
possible that those who had taken HRT were more likely to respond than those who
had not, leading to an overestimate of prevalence of HRT use. This is consistent
with the over representation of European women in our sample (92% versus the
2001 census for the same age group of 81%) who are more likely to take
HRT.4
However, this should not affect the internal comparisons or
changes with time. Although the decline in HRT-use was not statistically
significant, sales data released by Pharmac show a similar decline in use over
the same time period.5 Another study of a
non-random sample of HRT users in New Zealand—identified between 2000 and
2002—showed that 40% of the women had stopped taking HRT 6 months after
the release of the WHI results—very similar to the 36% reported in our
study.6
Our questionnaire was developed from the North and Sharples
study4 enabling us to directly compare the two
studies and assess the changes in HRT use in New Zealand over time. When looking
at the prevalence of HRT use in New Zealand, North and Sharples found an
increasing trend from 1991 (12%) to 1997 (20%). This was attributed to an
increased rate of prescribing for coronary artery disease prevention. The
prevalence in June 2002 was less than that in 1997 at 15%.
A contributing factor to the fall in prevalence from 1997 to
2002 may have been the publication of revised HRT guidelines in May 2001 that
did not support the use of HRT for coronary artery disease
prevention.7 Indeed, only 1 user out of the 48
users of HRT in June 2002 was taking it for the prevention of coronary artery
disease.
As recorded previously, symptomatic relief was the main
reason for HRT-use in this study, both in June 2002 and currently. Prevention of
osteoporosis was given as a reason by 40% in June, slightly lower than in 1997.
This may be due to increased use of other drugs to prevent osteoporosis.
Oestrogen-only preparations were the most commonly used type of HRT at 60% in
June 2002. This is higher than was previously found (1997—47%). The
proportion of women taking oestrogen-only preparations who continued after June
2002 was greater than among those taking combined preparations. This shows that
the 2002 research findings (which related to combined HRT only) had
disproportionately impacted on such use.
Our study is the first to explore how women heard the new
information on HRT and how this affected their use and opinions. More than half
of these women said their viewpoint had been influenced by what they had heard.
A predominant theme was the belief that menopause was a natural process, with
women preferring to either use no medication or natural remedies. It was
anticipated that there would be a difference of opinion between those who had
ever taken HRT and those who had never taken HRT. This was on the basis that
those who had taken it did so because menopausal symptoms had adversely
affecting their lives and they had received benefit from therapy. Indeed, those
who had ever taken HRT were much more likely to look upon it favourably than
those who had never used it.
With recent media hype, it was presumed that those women who
recalled hearing recent information would have more negative views on HRT. In
fact, both groups (information heard vs. not heard) held predominantly negative
views about HRT. Nevertheless, 73% of those women who continued HRT felt
comfortable about taking it. With relation to current guidelines acknowledging
that HRT is an effective treatment for troublesome hot flashes and night
sweats,3 it may be that those women who
continued taking HRT were indeed suffering from these severe symptoms.
We could find no trials assessing the best way to stop HRT.
It seems biologically plausible that gradually reducing the dose would avoid a
recurrence of menopausal symptoms. One of the aims was to assess the methods and
effects (if any) of discontinuation, but the small numbers meant no conclusions
were able to be drawn on this topic. Further study is required on the
appropriate time period over which to stop HRT, or other alternative strategies
for stopping.
We were interested in assessing the quality of information
released since the WHI study, as reflected in what women had taken on board and
how accurate their knowledge was. Although those who had heard any recent
information were better informed than those who had not, there was a lot of
uncertainty—highlighted by the fact that 34% of those women that had heard
information were unsure as to the effect of HRT on coronary heart disease.
Indeed it may be unrealistic to expect women to recall all
this information, given its complexity and the major changes in understanding
about benefits and harms of HRT-use over time. Since our survey was undertaken,
more information on the risk of breast cancer with HRT has been published, which
has added to the complexity by suggesting that the risks of breast cancer with
combined HRT are considerably greater than with oestrogen
alone.8
In conclusion, it appears that women have responded
appropriately to the new information about HRT, but (while information is
available and has reached a wide audience) women are confused about what they
have heard. Therefore, media information must be supplemented by basic
information from authoritative sources.
Author information:
Irma Bilgrami, Katy Blower, Jason Feng, Georgia Stefanko, Eugene Tan; Trainee
Interns, Department of Preventive and Social Medicine, Dunedin School of
Medicine, University of Otago, Dunedin
Acknowledgements:
This project would not have been possible without the continuous support and
encouragement from Associate Professor Charlotte Paul and Mrs Sheila Williams
who we thank very much. We also thank our clients, Dr Mira Harrison-Woolrych and
Dr Tree Cocks (for initiating this survey and for their ideas); Debbie Payne
(for helping us with all the technical difficulties that we encountered); and
all the women who participated in this survey.
Correspondence: Irma
Bilgrami, Department of Preventive and Social Medicine, Dunedin School of
Medicine, University of Otago, PO Box 913, Dunedin. Fax: (03) 479 7298; email:
irmabilgrami@hotmail.com
References:
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| | Current
issue | Search journal |
Archived issues | Classifieds
| Hotline (free ads) Subscribe | Contribute | Advertise | Contact Us | Copyright | Other Journals |
|