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HIV
Poor Adherence Reported in Some of
the Microbicide Studies, AIDSMAP, 13 May 2005
Microbicides 2006: Poor adherence
reported in some of the microbicide studies
AIDSMAP, Theo Smart, Saturday, May 13, 2006
Online: http://www.aidsmap.com/en/news/B369A4A8-20DB-4E9A-9079-427F5507BD60.asp
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Women randomised to microbicides
currently being evaluated in the clinical efficacy studies, described at
the Microbicides 2006 Conference recently in Cape Town, report that they
do not always use the products as consistently as they should, and in
one study, adherence to the microbicides has been lower without condoms
than when condoms are being used.
Self-reported behaviour, particularly
around microbicide and condom use (and sexual behaviour in general), is
not always reliable but if these trends continue, it could make it more
difficult for those studies to provide clear answers as to whether the
products work or not. Numerous presentations at the Microbicides 2006
Conference focused on ways to improve acceptance, encourage longer-term
adherence — and to verify whether the products are being used or not in
the ongoing trials.
Confounding condoms
The investigators in the clinical efficacy trials of microbicides are in
the awkward position of needing to encourage participants in their
studies to use both the product to which they’ve been randomised (microbicide
or placebo) and practice safer sex and use condoms — but the trials
would have a better chance of reaching a clear conclusion about the
effectiveness of the microbicide if people did not actually use the
condoms.
According to Dr Elof Johansson of the Population Council, which is
conducting the phase III trial of the microbicide, Carraguard,
consistent condom use probably works better than the microbicide. ”“For
ethical reasons we have to promote condom use within the trial. In my 35
years of experience working with clinical trials, I’ve never been in
such a difficult situation were you have to promote another treatment
that will work as good, and probably better, than the product you are
testing. So we have to rely on non-compliance on the condom side and
compliance on the gel.”
Yet just the reverse — better adherence to condoms than the microbicide
— is being reported in some studies.
For example, in the Cellulose Sulfate trial in Nigeria, participants
reported using a condom for 90% of sexual acts in the past week, but
women reported using the microbicide less frequently for 83% of the sex
acts in the past week. Reports from the Savvy Nigeria study are similar
(88% using condoms, 78% using gel for sexual acts in the past week).
Such high condom use rates, if true and sustained, would mean that very
few women in the study may become infected — and that the trials may be
too small to reach a clear conclusion.
And muddying the picture even further, women in HPTN 035, which compares
Pro 2000 and BufferGel to a gel placebo or no gel, are reporting that
they use the microbicide less frequently when they don’t use the
condoms, which could confound the study’s ability to measure the effect
of the microbicide.
According to the study’s protocol chair, Dr Salim Karim: “In many ways,
we spend so much time within our trial promoting a highly efficacious
prevention method in the form of condoms, and we have depended to some
extent upon the fact that a condom will simply not be used on every
occasion; and in those particular instances where condoms are not used,
that we would have a high proportion of those women adhering to the gel.
So in a way we are looking for two conflicting things, non-adherence to
the condom and adherence to the gel and you can see the hazards and
problems that that particularly poses.” See table.
Gel and Condom Use During Follow-up in HPTN 035
Among participants assigned to gel,
number of last vaginal sex acts reported by 422 participants With gel
Without gel Total With condom 82% 18% 70% Without condom 57% 43% 30%
Total 74% 26% 100%
“In the last sex acts of 422
participants, we only have 30% of sexual acts where there is no condom
being used. If you look at adherence to gel, you’ll see that 74% of the
sexual acts included gel. But one of the issues however, is that if we
look at how well adherence to gel tracts with adherence to a condom. In
women who used condoms, adherence to gel is very good (82%); however, of
the women who did not use condoms, only 57% used the gel. So what we
have is a situation in which even when the condom is not be used, we
still have a problem with at adherence to gel,” he said.
The adherence issues in the MIRA study diaphragm study are even more
complicated because the experimental arm has two components: the
All-Flex diaphragm with Replens gel (a vaginal moisturiser). Overall,
adherence in the study overall is lower than expected but if that
weren’t trouble enough, women often don’t use the gel provided with the
diaphragm. Participants in the trial reported using condoms at last
sexual contact about 70% of the time (in both arms), while in the
diaphragm and gel arm, only slightly more—76%—of the sex was covered by
diaphragm, but the gel was only used in 50% of the last sex acts.
Acceptability studies
Such low adherence could indicate that
there is a problem with product acceptability in this setting, for both
the diaphragm and for the gel.
Acceptability studies are usually conducted in the early stages of
product development and clinical testing, in order to understand women
(and men’s) preferences about a product, to help product developers find
acceptable formulations, delivery mechanisms, and packaging designs. All
of the current crop of microbicides had been extensively tested before
proceeding into advanced stage trials, and in general, product
acceptance has been high. These studies have been cross-sectional,
however, and haven’t tracked temporal changes in adherence.
Even so, a number of acceptability studies presented at the conference
suggested that could be room for improvement in the design of some of
the products — especially the diaphragms, which are not widely available
in many resource limited settings or familiar to the women there.
In one Brazilian study, 244 women and their male partners were asked to
evaluate three delivery devises; plastic applicators (that are inserted
into the vagina to deliver a set quantity of microbicidal gel),
diaphragms and intravaginal rings. Most of the complaints were about the
diaphragms.
More women in the study wanted to remove the diaphragm immediately after
sex — but to be effective, diaphrams need to remain within the vagina
for 6-24 hours after sex, depending upon the model. According to another
study in Madagascar, women also want to remove the diaphragm after sex
so that they can douche themselves. Note that this aspect of adherence
may not be adequately addressed in many of the ongoing trials — and that
douching could also interfere with the effectiveness of gel microbicide.
In a pilot study of the MDP301 study, for example, in Uganda, “some
women viewed gel use instructions (requirement not to wash inside the
vagina until one-hour after sex) as difficult to follow over a long
period of time.”
The design of the diaphragm could also be a problem. “Most of the women
and about 60% of the men suggested changes for the diaphragm; mainly
that it should be smaller, more flexible and have a thinner rim without
a spring,” according to Ellen Hardy of the Universidade Estadual de
Campinas in Sao Paulo, Brazil. In another study in couples with no
previous experience using diaphragms in South Africa, Thailand, and
Dominican Republic, complained that the All-Flex diaphragm was more
difficult to handle, insert, and less comfortable than the SILCS
diaphragm.
However, according to one poster, in the MIRA study, clinicians worked
with the patient to determine the most comfortable, correct fitting
diaphragm size — and only a few patients had serious problems with
inserting the diaphragm.
And yet the study did note that although the Replens gel facilitated
diaphragm insertion, the lubricant made the diaphragm difficult to
handle — which could be one reason why adherence to the gel was lower.
Other studies have also noted that “messiness” is a commonly reported
problem associated with use of both diaphragms and gel.
Messiness or excessive wetness has frequently been cited as a drawback
of some of the gels, and could be part of the problem with poor
adherence in a number of the studies.
“Not surprisingly, gels increase lubrication” said the key note speaker
on acceptability studies, Professor Joanne Mantell, a public health and
social scientist from Columbia University, “but preferences regarding
lubrication vary. Some studies show that women do not like a product
that is too messy or drippy, although it is difficult to know what the
underlying meaning is of excessive vaginal fluids.”
In fact, in the Brazilian study on delivery systems, “without meaning
to, we obtained some information on the gel that we were using, that
just came out, we didn’t ask it specifically,” said Dr Hardy. “They said
that would like to use a smaller amount each time, and that this gel
should be less fluid to prevent excessive lubrication or messiness.”
It should be pointed out that most of the various microbicides in
advanced studies have specifically been designed to be less messy. Even
so, the lubrication does not go unnoticed — including often, by the male
partner. According to a comment made during one discussion of
acceptance, regular male partner’s can tell “when something is different
down there.”
While lubrication may be desirable for sex in Western society, in some
African cultures, men prefer dry sex. Male partners may interpret too
much lubrication, especially before sexual intercourse, as meaning that
the woman is unfaithful, has an sexually transmitted infection or has
poor vaginal hygiene. Several studies noted that regular male partners
are occasionally problem for adherence in some studies — particularly if
they were not informed of the woman’s participation or involved in the
study from early on. (LINK)
But the acceptability or adherence problems in these studies could also
simply be due to logistics, e.g., having access to and being able to
insert the gel before sex occurs could be the issue. Several studies
noted that storage and disposal of gel applicators and privacy needed to
assemble the applicator and apply the gel in advance of sexual activity
can be problematic in resource limited settings.
Product adherence in clinical trials is generally higher than when
products are on the market, so getting to the bottom of these problems
is crucial in order to anticipate problems in up-take and adherence that
could occur and actually be worse once an effective product goes to
market.
Counselling messages
One of the reasons why there is usually
higher product use is because of high levels of staff support and the
desire to please staff. But another possibility is that the staff
counselling participants in the studies could be communicating the mixed
messages about using the microbicides.
Although there’s only been a limited number of studies looking at the
role of providers (from doctors to counsellors who are providing safe
sex counselling), they’ve found that “providers say that they are
reluctant to counsel people to use a ‘half-safe method’ especially when
condoms offer a higher level of protection. The concept of harm
reduction has not been incorporated into sexual risk reduction
counselling in most settings, especially among family planning
providers, who typically aim to promote the most effective contraceptive
methods,” Prof Mantell said.
Preliminary indications are that this could at least be part of the
problem. According to Dr. Karem, in HPTN 035, “the team’s initial
exploration suggests that there may have been some misunderstanding of
counselling messages among study staff and participants. So we’re
looking at how to address this challenge and refine the kinds of
messages that might be used to improve adherence to gel. Over the
weekend before the conference, the protocol team got together to develop
enhanced adherence counselling messages and scripts for immediate use at
all the sites.”
Likewise, in the MIRA diaphragm study, they are focusing on the study
staff, conducting in-person meetings trying to reinforce the importance
of using the gel. They discuss how staff should respond to a patient who
reports that either she or her partner does not want to use some/all
products, stressing the importance of use for study results with
role-playing and so on.
On-microbicide analyses
Such adaptability over the course of
the study may overcome the adherence challenges faced in these studies —
but in case it doesn’t always work, performing on treatment or
on-adherence analyses could salvage the ability of these studies to
determine whether the microbicides are effective in the subset of women
who actually use the products.
But since self-reports are not always reliable, some of the studies are
looking for more concrete evidence that the products have been used. In
the MDP301 study they are looking at gel returns after a pilot study
found that, if asked, women will return virtually all their used and
unused applicators. This practice also allows the pharmacy staff to flag
the participants whose gel use is low, who then receive intensive
counselling to achieve overall higher gel adherence.
The proof is in the put-in
In the Carraguard study, however, they
were concerned that an opened applicator may not necessarily have been
inserted and used, so they developed to distinguish applicators that
have been inserted into the vagina. The method uses a safe food dye
powder used in the manufacture of chocolate that turns the applicator
tip blue if it has been exposed to vaginal mucous — and can be easily
and successfully performed by technicians at all the trial sites. The
system does have limitations — sex may not have actually occurred
afterwards or it may not have been the actual trial participant.
Said Dr Johansson, “we have developed a way of testing whether an
applicator has been inserted into the vagina or not. We don’t know in
whose vagina but we know if its been used.”
References
See Overview article.
Mantell J. Acceptabilityresearch:
Outcomes & future direction. Microbicides 2006 Conference, Cape Town,
key note address #1, 2006.
Manickum S et al. Challenges in introducing vaginal diaphragm among
women in a phase lll HIV prevention clinical trial. Microbicides 2006
Conference, Cape Town, PB44, 2006.
Hebling EM, Hardy E, De Sousa MH. Devices for the administration of a
vaginal microbicide: suggestions on how to make three devices more
attractive. Microbicides 2006 Conference, Cape Town, OC6, 2006.
Hardy E, Hebling EM, De Sousa MH. Devices for the administration of a
vaginal microbicide: use difficulties, adherence to use and preferred
device. Microbicides 2006 Conference, Cape Town, PC23, 2006.
Kilbourne-Brook M et al. SILCS Diaphragm: acceptability of a
single-size, reusable cervical barrier by couples in three countries.
Microbicides 2006 Conference, Cape Town, PC33, 2006.
Wandiembe SP et al. Potential barriers to adherence to product use and
cohort retention in microbicides efficacy trials. Microbicides 2006
Conference, Cape Town, OB9, 2006.
Kaganson N et al. Gel returns during phase III trials. Microbicides 2006
Conference, Cape Town, OB11, 2006.
Govender S. Evaluation of Microbicide Applicators to Determine Vaginal
Use in the CarraguardTM Phase 3 Clinical Trial. Microbicides 2006
Conference, Cape Town, OB12, 2006.
Legardy-Williams J et al. Attitudes and Beliefs about Vaginal Cleansing
among Women, Men, and Healthcare Providers in Antananarivo, Madagascar.
Microbicides 2006 Conference, Cape Town, OC19, 2006.
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