This is the first study to assess future willingness to participate in prevention research studies among community-based surveys of gay and bisexual men in Scotland. First, there are some limitations to note when considering these results. This was a bar and sauna sample so only men who visit the venues surveyed have the opportunity to participate, and our findings should be interpreted within this context. Willingness to participate in prevention research could be different among men who did not answer these questions and in the wider population of gay men who do not frequent the commercial gay scene. Participants were only asked if they would be willing to participate in future research studies, not why this may or may not be the case. As the question was hypothetical, we cannot assume that willingness would equal actual participation. No description of what could be involved in taking part in such research was provided. However, the results provide interesting insight into men’s willingness to participate in such studies and this is important for planning future interventions and HIV prevention efforts.
Just over three quarters of the men surveyed reported that they were willing to participate in future HIV prevention research studies, with greater willingness to participate in biomedical than behavioural studies. It is particularly interesting to note that willingness to participate in these studies was considerably higher than the level of willingness to participate in male circumcision research in this population [8
]. The former have to date, for the most part, not shown a positive effect on reducing HIV transmission [4
], while the latter is the biomedical intervention with, arguably, the greatest effect on (albeit hetero) sexual transmission [4
]. This raises the query of whether men are aware of male circumcision as HIV prevention, and its limited potential as an intervention for MSM [7
], or whether there is some other reason that such an intervention is unattractive to them. It is also interesting to note that willingness to participate in biomedical research was lower among men who did not provide oral fluid samples to be tested for HIV. When men who did and did not provide oral specimens were compared only age was significantly different, with men aged 26 + years less likely to provide samples [8
]. It is possible that men who did not provide samples have concerns about participating in any kind of biomedical research.
A review of (mainly North American) HIV vaccine preparedness studies found willingness to participate in vaccine trials ranged from 23% to 94% among MSM [23
]. Here, almost two-thirds of men expressed willingness to participate in HIV vaccine research studies. This is considerably higher than the proportion reported in the only other UK study of this topic among MSM; 23% reported likelihood of participating in an HIV vaccine trial in a London gym-based survey of MSM [24
]. It is possible that men see these as having the greatest potential benefits to themselves and their community, and both personal and altruistic reasons have been identified as motives for participating in previous trials [25
]. However, a US study of MSM’s knowledge and acceptability of biomedical interventions found vaccines were the most commonly known intervention types [26
], so it could be that men are simply more likely to have heard of these. Half of the men surveyed said that they were willing to participate in a rectal microbicide research study. This compares to a previous American study, in which around two-thirds of gay men reported they would be willing to participate in microbicide trials [27
Although one vaccine trial has reported (limited) positive results [28
], it is unlikely that a vaccine will become available in the immediate future, with considerable further research required [28
]. So far, all of the microbicide candidates are for vaginal rather than rectal use [4
], and few acceptability research studies have been conducted among MSM [30
]. If HIV vaccine and rectal microbicide trials were to be initiated with MSM in the UK, further research would be required to assess the factors that could facilitate or prevent participation in this population. Education and community mobilisation could increase willingness to participate in such studies [31
], and consideration should be given to describing trial protocols to potential participants as part of assessing willingness to join research projects.
There is continuing interest in the potential for behavioural interventions among MSM in Scotland [3
], and over half of the men surveyed indicated willingness to participate in this type of research. However, men who were treatment optimistic, and less worried about HIV now treatments had improved, were less likely to be willing to do so. Although only a minority of MSM are optimistic (see Table and as noted elsewhere [32
]), associations between treatment optimism and sexual risk behaviour have been recognised [32
]. Increases in sexual risk behaviour cannot be fully accounted for by increasing treatment optimism [35
], but this issue nevertheless remains a challenge and something to consider during recruitment for a behaviour change research study.
Future willingness to participate in vaccine, microbicide or behaviour change research studies was greater among service users, particularly among men who reported having had an STI in the past 12 months. This suggests existing services may be appropriate venues within which to recruit men for future research. Intervention delivery in these settings has previously been identified as a characteristic of successful interventions among people living with HIV [38
], though a wider range of recruitment settings may be necessary to recruit sufficient numbers, and relevant risk groups, of MSM [39
]. Willingness to participate in behaviour change was also higher among HIV-positive men, a group for whom, to date, behavioural interventions have proven largely ineffective [38
Previous research found men at higher risk of HIV were more likely to be willing to take part in HIV vaccine trials [23
]. Here, the lack of association between sexual risk behaviours (other than having had an STI in the past 12 months) and such willingness suggests it may be difficult to recruit adequate numbers of men at higher risk of HIV (particularly beyond the clinical setting); a finding that has implications for the design (and cost) of such future research. Sherr et al. estimated that a minimum of 15,000 HIV-negative men would need to be approached to recruit 1,000 high-risk HIV-negative men into a vaccine trial (based on a willingness to participate rate of 6.9%) [24
]. Our study identified 189 men (12.5% of the total survey sample) who tested HIV-negative, reported UAI with partners of unknown or discordant HIV status in the past 12 months and were willing to participate in an HIV vaccine research study. With a 70.5% survey RR, over 10,000 men would have to be approached to achieve a sample size of 8,000 men in order to recruit 1,000 such high-risk HIV-negative men into a trial.
To be adequately powered to show effect on HIV incidence, trials require large sample sizes. A definitive phase III trial with 95% power to detect an effect with a 60% effective vaccine would require approximately 6,000 participants from a population with annual 2% HIV incidence [40
]. Based on the figures noted above, 60,000 men would have to be approached to achieve this sample size, requiring large multi-centre (and even multi-country) studies.
Combination prevention, which incorporates biomedical and behavioural, as well as social and structural, interventions has been argued as the way forward for HIV prevention [41
]. The detailed assessment of the acceptability and feasibility of such interventions is vital [10
], particularly to avoid the flaws that can lead to ‘flat’ results [4
]. Our findings suggest recruitment of high-risk men, who have the potential to benefit most from such interventions, is likely to be challenging, time consuming, and hence costly. The best means of facilitating this should be examined through feasibility studies, prior to initiating intervention trials.