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  • HIV pre-exposure prophylaxis (PrEP) is highly effective at reducing the risk of acquiring HIV
  • Researchers surveyed more than 1,000 men who have sex with men across Canada about PrEP
  • Although many men in Canada were eligible for PrEP, only about 25% had used it

HIV infection disproportionally affects gay, bisexual and other men who have sex with men (MSM) in Canada and other high-income countries. HIV pre-exposure prophylaxis (PrEP) currently consists of two anti-HIV drugs—tenofovir + FTC. Studies have found that the combination of these drugs is highly effective at reducing the risk of HIV infection in MSM.

A team of researchers in Montreal, Toronto and Vancouver surveyed MSM in those cities about PrEP and published their findings in the journal CMAJ Open. There were 1,100 participants who knew about PrEP and who disclosed that they were either HIV negative or did not know their HIV status. According to Canadian PrEP guidelines, these men met the criteria for using PrEP. However, only about one-quarter of the men had used PrEP in the six months prior to being surveyed.

The research team found that non-use of PrEP by the men was linked to the following factors:

  • not feeling that they were at sufficiently high risk for acquiring HIV
  • viewing PrEP as not very effective
  • not having a primary care doctor
  • not having medical insurance

PrEP is a key part of a strategy to help reduce the spread of HIV. In order for Canada to make progress in reducing new cases of HIV infection, issues that pose barriers to the use of PrEP need to be removed.

Study details

Researchers analyzed data collected between February 2017 and August 2019 in a study called Engage. The analysis was based on data collected from each participant at one point in those years.

The 1,100 participants had heard of PrEP and disclosed that they were either HIV negative or did not know their HIV status. Researchers summarized the profile of these participants in the following way:

  • half were between 17 and 30 years old and the other half were between 30 and 73
  • the vast majority were cisgender men (between 89% and 99%, depending on where they lived)
  • most identified as gay (between 81% and 89%, again depending on where they lived)
  • most were born in Canada (at least 60%)

Awareness of PrEP was relatively high across all three cities.

Results – Reasons PrEP was not used

The research team stated that participants reported many reasons for the non-use of PrEP, including the following:

Personal reasons

  • “in a relationship with a main partner”
  • not feeling sufficiently at risk of HIV
  • “not knowing enough about PrEP to determine whether it was right for them”
  • “perceiving PrEP to not be very effective”

Healthcare-related reasons

The researchers stated that participants who disclosed the following were not likely to use PrEP:

  • “if they thought that they were unable to find a doctor accepting of their sexual behaviours to prescribe PrEP”
  • did not disclose having male sexual partners to their primary care provider
  • did not have a primary care doctor

Cost and other issues

The researchers found that people with the following issues were less likely to use PrEP:

  • lacking prescription drug coverage
  • “being concerned about the cost of PrEP”
  • worrying about side effects from PrEP

Trends in time

As mentioned earlier, participants were recruited for the study over a few years (2017 to 2019). Researchers found that participants recruited in 2019 were more likely to use PrEP compared to those recruited in earlier years.

Meeting the guidelines yet not on PrEP

The researchers stated: “Using the Canadian HIV PrEP clinical guideline and baseline data from the Engage cohort study, we estimated that about half of HIV-negative or HIV-unknown [participants] in Montréal, Toronto and Vancouver could benefit from PrEP. We also found that 4 of 5 [participants] who met clinical recommendations did not use PrEP.”

Potential interventions

After reflecting on their findings, the researchers suggested the following interventions:

  1. “Improving access to PrEP should build on components of PrEP literacy, providing related information to individuals and communities. Perceived need, a function of both knowledge about PrEP and one’s perceptions about personal HIV risk, could be reinforced for [MSM] considered most at risk for HIV. Therefore, community information campaigns and peer-based programs could be used to guide [MSM] regarding the scope of their HIV risk and the potential benefits of PrEP. This could ultimately affect motivations to use PrEP and create new community norms regarding prevention.”
  2. “Interventions such as community outreach to improve linkage [to] and knowledge about PrEP care [in addition to] removal of medication cost could increase PrEP uptake.”
  3. “Finally, work is needed to improve PrEP awareness among primary care networks, including continuing professional development programs on PrEP and general sexual health for [MSM].”

Bear in mind

The Canadian study’s findings are similar to what has been reported from studies in the U.S. This adds to the robustness of the Canadian study’s results and also underscores that MSM face barriers to accessing PrEP.

The United Nations Joint Programme on HIV/AIDS (UNAIDS) has issued “targets” to which cities, regions and countries can aspire to reduce the spread of HIV. One of those targets is that by 2025, 95% of people at risk for HIV infection will be offered and will use combination prevention options. If Canada is to meet this goal, more people who want PrEP should be able to get it.

—Sean R. Hosein


Pre-exposure prophylaxis (PrEP) resources and tools – CATIE

Study underscores need for HPV screening and vaccination in gay and bisexual PrEP users – CATIE News

Australian researchers study syphilis in men who use HIV pre-exposure prophylaxis (PrEP) – CATIE News

Transgender people found to have effective levels of HIV prevention drug – CATIE News

Long-acting injectable drug prevents HIV – CATIE News

2025 AIDS Targets – UNAIDS


Cox J, Apelian H, Moodie EEM, et al. Use of HIV pre-exposure prophylaxis among urban Canadian gay, bisexual and other men who have sex with men: a cross-sectional analysis of the Engage cohort study. CMAJ Open. 2021 May 21;9(2):E529-E538.