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.