About The Study

CTN 325 aims to investigate the real-world effectiveness of interventions to improve initiation, adherence, and retention in HIV treatment in Ontario. Specifically, this study focuses on priority groups within the HIV community who may face personal and systemic factors that can negatively affect engagement in care and, ultimately, HIV-related outcomes. These groups include youth, people who inject drugs, African, Caribbean and Black people, Indigenous people, and men who have sex with men, among others. Overall, this study will inform policy and practice at the various stages of HIV care.

About The Disease

The cascade of HIV care refers to the ongoing process of how people are diagnosed with HIV, initiate treatment, adhere to that treatment, and remain consistently connected to care throughout their life. We know that each of these stages within the cascade of care is important to maintaining optimal care and outcomes. We also know that different people face different barriers along the cascade of care that can affect how likely they are to have success at each stage. Specifically, people who experience social marginalization, like the priority groups listed above, face unique circumstances that can affect treatment initiation, adherence, and retention. These unique circumstances mean that various efforts to improve the cascade of care may not be effective for all groups, and interventions that are tailored to each group’s needs are required. Overall, interventions to address the cascade of care may not be as effective in the real world as they are in a controlled research environment. Therefore, CTN 325 aims to understand the real-world factors that affect the success of interventions to improve HIV treatment initiation, adherence, and retention in priority populations and others who face social marginalization.

Study Approach

CTN 325 will take place in two phases. The first phase will involve a survey of HIV clinics in Ontario. These surveys will ask HIV care providers and staff about a list of interventions identified to be effective in a systematic review, whether they have been tried at the clinic, factors that affect their implementation, and current strategies used at the clinics. The second phase will include interviews with health workers and a diverse group of people living with HIV. These interviews will focus on key issues such as experiences with adherence and retention strategies and patient preferences related to these interventions. The information gathered in both stages will be combined to identify and prioritize effective interventions, understand what is needed to expand and scale up the interventions, and other recommendations.


An electronic survey was conducted with 20 care providers across eight clinics to understand some of the barriers and facilitators to the implementation of HIV care cascade interventions in Ontario. The results highlighted that, although most participating clinics implement interventions known to be effective in improving the care cascade, half of the respondents mentioned that lack of expertise and resources are barriers to implementation. This survey will be followed by in-depth interviews to learn more.

Eligibility Requirements


Staff of HIV clinics in Ontario who provide care to people with HIV and people living with HIV in Ontario are eligible.

Additional Information

If you would like to take part in this study or want more information, please contact the principal investigator.

Principal Investigator

Here’s who is leading this study.

Can’t find what you’re looking for? Email ctninfo@hivnet.ubc.ca.