Investigating the limitations with the snowball model in context of the TAP study

The Treatment and Prevention study (TAP) is a world-first clinical trial of DAA treatment for a group of people who inject drugs (PWID). Individuals are treated for hepatitis C together with people with whom they inject drugs, in order to prevent reinfection after successful treatment.

TAP study participants are asked how many people they have injected with (same time and place) over the past six months and how many in the past month. Despite often reporting injecting with many people, participants have mostly only brought a couple of friends into the study.

Objective

The study aimed to answer the following questions:

• What were the limitations to TAP participants bringing their whole injecting networks to receive DAA therapy as offered in the TAP study?
• If they were willing to participate, what factors limited their friends from participating in DAA treatment?
• What changes could be made or what services could be offered to facilitate the full network in seeking/participating in treatment?
• What attitude shifts or behavioural changes must take place to make seeking DAA favourable?
• What promotion strategies or changes could the health system implement to facilitate these shifts?

Approach

This study involved a mixed method approach.