18 March 2025
Despite the growing body of evidence on effective healthcare interventions like hepatitis C dried blood spot testing and needle and syringe programs to improve the health and well-being of people who use drugs, translating these findings into practice remains a significant challenge.
Even Direct-Acting-Antivirals for hepatitis C- which we know have a 95% cure rate – are useless if they do not reach the right people at the right time. So how do we identify and overcome the barriers that are stopping these proven interventions and treatments from happening?
Enter, implementation science.
“Implementation science is about translating research into practice,” explains Dr. Guillaume Fontaine, who leads the McGill University RISE3 Implementation Science Lab and is an expert in using these methods to improve health outcomes for marginalised groups. He emphasises that it is not enough to just have evidence-based interventions—these need to be effectively implemented at the ground level to create tangible benefits.
The Four-Step Framework for Change
According to Dr. Fontaine, although there are various frameworks for implementation science, one of the most common – and his preferred – is the process outlined in French et al. (2012), which includes four essential steps:
Step 1. Who needs to do what, differently?
Determine the target clinical behaviours to change by reviewing evidence-practice gaps (e.g., providing pre-test counselling, conducting HCV antibody screening). Clearly define the specific behaviours, the individuals performing them, and when and where these behaviours occur in care pathways.
Step 2. Using a theoretical framework, which barriers and enablers need to be addressed?
Select a theoretical framework to guide the assessment of barriers and enablers to these clinical behaviours. Use informal methods (e.g., consultations with key stakeholders), qualitative methods (e.g., focus group discussions, interviews) or quantitative methods (e.g., questionnaire) to identify the barriers and enablers that could influence the target behaviours.
Step 3. Which implementation strategies could overcome the modifiable barriers and enhance the enablers?
Select implementation strategies (e.g., provider education, training, quality assurance, champions) that might be effective, locally relevant, acceptable, and feasible to overcome identified barriers and enhance facilitators to change. Selection of strategies should be based on matrices recommended by determinant frameworks, empirical evidence, and engagement with end users.
Step 4. How can implementation be measured and understood?
Decide how change in implementation can be robustly and feasibly measured, including appropriate implementation outcomes (e.g., acceptability, feasibility, adoption, sustainability, cost).
“The four-step process is designed to ensure that implementation is methodical, with careful consideration given to context and barriers,” Dr. Fontaine notes.
Each step in detail, with examples
Step 1 in the implementation process is identifying who needs to change their behaviours and what those changes should look like. The AACTT (Action, Actor, Context, Target, Time) framework, introduced by Presseau et al. (2019), clarifies who needs to take action and when.
By defining the roles of healthcare providers, patients, and other stakeholders, implementation science helps pinpoint the behaviour changes necessary for success. This approach was explored in a recent study by Fontaine et al. (2024), which examined barriers and enablers to hepatitis C testing among people who inject drugs in Montreal.
We examined the entire HCV care cascade—screening, linkage to care, treatment initiation—and identified key pain points. After mapping the actions and stakeholders, we met with them to focus on the biggest issues, such as a lack of resources, time, and skills for offering HCV antibody screening. We also explored factors affecting test acceptance among people who use drugs. This process helped us pinpoint the key steps to focus on for addressing barriers and facilitators at the next stage.
Dr. Fontaine.
Once the necessary actions have been identified, the next challenge (step 2) is assessing the barriers preventing these actions. Cane et al. (2012), introduce a theoretical framework for evaluating barriers, focusing on psychological, organisational, and environmental factors affecting implementation.
Capabilities refer to factors like a lack of knowledge, skills, and tools to help people practically. The second area is motivation—anything related to their goals, feelings, intentions, and so on. And the last, but really important domain, is physical and social opportunity. This includes resources, social support, social influence, and external factors, which can be much harder to address in some contexts.
In harm reduction programs aimed at people who use drugs, barriers like lack of training for healthcare workers, stigma surrounding drug use, and inadequate funding often impact successful implementation.
After identifying the barriers, the next step (step 3) is to implement selected strategies. According to Proctor et al. (2013), Powell et al. (2015), effective implementation strategies require a nuanced understanding of the settings in which they are applied. Their work provides strategies such as stakeholder engagement, training, and support systems to facilitate the adoption of new practices. Dr. Fontaine (2024) recently conducted the largest systematic review on the effects of 19 different implementation strategies to support evidence-based practice in nurses and improve patient outcomes
The National Australian Hepatitis C Virus (HCV) Point-of-Care Testing Program
The National Australian Hepatitis C Virus (HCV) Point-of-Care Testing Program offers a clear example of applying implementation science. Between July 2023 and March 2024, Dr. Fontaine and the team mapped the program’s components, activities, and outcomes, identifying 40 implementation strategies to address multilevel barriers to implementation.
These included developing and distributing educational materials, conducting site readiness assessments, and providing local technical assistance. The program also emphasised stakeholder engagement, efficient communication and continuous operator training and quality assurance.
The program has over 100 sites and Dr. Fontaine points out that “implementing these changes isn’t a one-size-fits-all approach, and the key to success lies in understanding the local barriers and strengths before launching any intervention.”
Measuring success
Implementation science doesn’t stop at intervention. One of its key strengths is the focus on evaluation (step 4)—measuring the success of interventions and ensuring they continue to be effective over time. By consistently evaluating the impact of implemented strategies, healthcare systems can refine their approaches and adjust to evolving challenges.
More specifically, implementation science evaluation frameworks emphasise three levels of outcomes: (1) implementation outcomes, (2) service outcomes, and (3) client outcomes, as outlined in Proctor’s Taxonomy of Implementation Outcomes.
The central idea is that if we do a good job of addressing key barriers to implementation using appropriate strategies, we will achieve better implementation outcomes (e.g., acceptability, feasibility, fidelity, adoption, sustainability), better service outcomes (e.g., efficiency, timeliness, equity, patient-centeredness), and better client outcomes (e.g., improved health status, reduced morbidity and mortality, enhanced quality of life).
For example, Yakovchenko and colleagues have examined how implementation strategy use influences hepatitis C treatment uptake. Their research shows that specific strategy configurations are directly linked to higher treatment initiation rates (Implementation Science, 2017; Medical Care, 2020; Implementation Science, 2019), emphasising the need for strategic implementation approaches to improve HCV care.
Want to learn more?
Through data-driven decision-making, implementation science is not just improving care for people who use drugs but ensuring that those improvements are sustained and scalable. “By using implementation science, we can make healthcare more accessible and effective for people who need it most,” concludes Dr. Fontaine.
For those interested in learning more about the role of implementation science in achieving hepatitis C elimination, Dr. Fontaine recently authored a Comment in The Lancet Gastroenterology & Hepatology titled The Urgent Need for Implementation Science to Achieve Hepatitis C Elimination (2025). This article provides an in-depth discussion on how implementation science tools can be leveraged to bridge gaps in HCV prevention, testing, and treatment, ensuring that interventions are effective, equitable, and sustainable.
