July 2002, Vol. 8, No. 1

Microbicides
Motivations for and Barriers to Study Participation

What factors motivate people to participate in clinical trials? While participants may potentially reap benefits, the products being tested are, by definition, unproven. To gain insight into this question—particularly in reference to trials of microbicides—Population Council researchers, with colleagues at the Thailand Ministry of Public Health–U.S. Centers for Disease Control and Prevention Collaboration, recently assessed the interests and concerns of women in Chiang Rai, Thailand regarding participation in microbicide clinical trials. Findings from this and similar research may prove valuable for selecting trial sites, estimating enrollment rates, and tailoring trials to best meet women’s needs. 

Microbicides are products, such as gels, creams, or other formulations, designed to prevent sexually transmitted infections, including HIV, when applied vaginally or rectally before intercourse. While no microbicides are currently approved, a number of them—including one developed by the Council, known as Carraguard™—are being tested. 

Representative population 
Many effectiveness trials of candidate microbicides have been conducted among sex workers. This practice, however, is not ideal. “Sex workers may have mucosal irritation from frequent intercourse,” says Population Council researcher Charlotte Ellertson, “which might negate benefits of an otherwise effective microbicide.” Many researchers would prefer to test microbicides among women who are more representative of the general population.

 Investigators chose to study women in Chiang Rai, the northernmost province of Thailand, because the region has a high rate of HIV infection. They used a structured questionnaire to interview 370 women recruited from an antenatal and a family planning clinic. The survey questions were developed on the basis of findings from a series of focus group discussions and in-depth interviews of women and men in the province; only women participated in the interviews. Before being interviewed, the women attended a brief informational session on microbicides and the requirements of a hypothetical clinical trial. 

Eleven of the survey questions tested comprehension of information presented on microbicides and clinical trials. Eighty-two percent of the women answered eight or more of these questions correctly, while only 10 percent answered five or more questions incorrectly. After the short informational session, women were able to understand the most important concepts about microbicides and participation in clinical trials. 

Motivations and barriers
The researchers asked the participants to rank each of 13 motivations for trial participation as “most important,” “very important,” “somewhat important,” or “not at all important.” Eighty-two percent said that “getting tested for HIV during trial participation” was very important, whereas only 34 percent thought that getting reimbursed for travel costs was very important. Nearly half the women, however, thought this factor was somewhat important. When asked which motivation was the single most important in deciding to join a trial, “doing something good for women’s health” was most often (35 percent) cited. 

The researchers also asked participants to rank each of 19 barriers to trial participation as “most important,” “a major problem,” “a small problem,” or “not a problem.” Forty-six percent of participants said that the fear that using a microbicide might cause their husband to feel protected and thus to have more sexual partners was a major problem. Forty-two percent of women thought that “deciding to participate in the trial without your husband’s consent” was a major problem. More than 60 percent of women, however, stated that the need for regular follow-up was not a problem, and 67 percent said that fear of receiving HIV results was not a problem. When asked to name the single most important barrier to trial participation, women most often (27 percent) cited the fact that long-term side effects of a microbicide are not known. 

Most women (two-thirds) said they thought they would be willing to participate in a trial, but wanted to consider the matter further. Roughly 6 percent asserted they were definitely willing to participate in a trial, and less than 3 percent said they were not at all willing to participate. 

Noting that a similar study conducted in Bangkok regarding vaccine trials found a much higher proportion of people (51 percent) definitely willing to participate in trials, Council researcher Kelly Blanchard stated that “some uncertainty about trial participation may come from a lack of familiarity with microbicides as a concept. Information for potential trial participants and good counseling might mean more women would be willing to participate.” Given that the two factors most frequently cited as a major problem involve women’s husbands, the researchers concluded that outreach and education for men about microbicides would also be useful.

Source
Tharawan, Kanokwan, Chomnad Manopaiboon, Charlotte Ellertson, Khanchit Limpakarnjanarat, Supaporn Chaikummao, Peter H. Kilmarx, Kelly Blanchard, Christiana Coggins, Timothy D. Mastro, and Christopher Elias. 2001. “Women’s willingness to participate in microbicide trials in northern Thailand,” Journal of Acquired Immune Deficiency Syndromes 28(2): 180–186.

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