Research for treatments, prevention and a cure
Page template: single-clinical-trials.php
Search terms : 

Clinical Trials

  • Clinical Studies

Prevention (PREV)

CTN 300: The Engage Study

HIV Prevention for Gay, Bisexual, and other Men Who Have Sex with Men

Print Friendly, PDF & Email

About the study (objectives)

Focusing on gay, bisexual, and other men who have sex with men (gbMSM), the Engage Study will measure and compare the factors that affect the effectiveness, access to, and availability of HIV prevention programs in major urban centres in Canada.

About the disease/condition (background/context)

Modern HIV prevention strategies can come in many different forms. Biomedical technologies such as pre-exposure prophylaxis (PrEP) and post-exposure prohpylaxis (PEP) have been successful in decreasing HIV transmission. Sociobehavioural prevention approaches, such as educational, counselling, and safer sex programs, especially in conjunction with other strategies, have also been effective. However, uptake and exposure to these programs differs between cities and between different groups of people.

CTN 300 will collect information on the factors that affect HIV risk behaviour, access to prevention and treatment programs, and other determinants of HIV, hepatitis C virus (HCV), and bacterial sexually transmitted infections (STIs). The collected data will be compared between cities (Toronto, Vancouver, and Montreal), allowing researchers to evaluate current HIV and STI prevention strategies and to identify gaps in care and the shortcomings of current programming.

Study Approach (methodology)

About 2400 HIV+ and HIV- participants will be enrolled between the three cities. The Engage Study uses a method called Respondent Driven Sampling (RDS) where selected community members invite potential participants through their social networks.

The study will use a series of biological tests to measure recent HIV and STI infections and determine prevalence. Questionnaires will also be administered to determine sexual risk taking behaviour, knowledge of and access to educational and biomedical HIV preventions programs, and other information. The data will be collected at baseline and 12 months and compared across cities and time points. Researchers will use this information to identify which programs are being accessed, which programs are associated with a decrease in HIV and STI prevalence, and other factors that are associated with engagement with care or recent infection.

Eligibility criteria 


  • Gender-identify as a man, including men who identify on the trans-masculine spectrum
  • 16 years of age or older
  • Reported sexual activity with a man in the previous six months
  • Received a RDS voucher for participation in the study, or was invited to be an initial “seed” participant
  • Ability to complete a computer-based questionnaire in English (each site) or French (in Montreal)
  • Ability to provide informed consent

Participating Sites


Ryerson University

British Columbia

BC Centre for Excellence in HIV/AIDS



Additional Information

If you would like more information on this clinical study, please refer to the principal investigator or visit

Principal Investigators:

Trevor A. Hart, PhD, C.Psych
Department of Psychology,
Ryerson University
350 Victoria Street
Toronto, ON

Latest News

Aging with HIV

| Uncategorized | No Comments

Today, more than half of all people living with HIV in Canada are 50 years or older. This is mostly because people are living much longer, healthier lives with HIV thanks to the success of antiretroviral therapy (ART).

Interpreting new international study results for the Canadian context

| Uncategorized | No Comments

CTN National Director Dr. Aslam Anis commented on new findings from study which found that the risk of transmitting HIV to a sexual partner is completely eliminated in people on ART.

Inaugural Steatohepatitis in HIV Workshop Launched

| Uncategorized | No Comments

The goal of this workshop is to provide a multidisciplinary view of the current state of nonalcoholic steatohepatitis (NASH) in HIV and establish a collaborative platform for related research projects.

Guest Blog: Dr. Kiffer G. Card

| Uncategorized | No Comments

Dr. Card, CTN Postdoctoral Fellow, provides an overview of his fellowship project, using national survey data to shed light on patterns of substance use and how they relate to HIV risk in gbMSM.

Research for treatments, prevention and a cure