Break the Cycle is a two-session, one-on-one, in-person intervention study designed to reduce the role persons who inject drugs (PWID) play initiating non-PWID into injection drug use. Study implementation is at two sites: New York City and Tallinn, Estonia. At baseline, quantitative data are collected via a structured computer-assisted personal interview, after which the intervention is conducted. At the 6-month follow-up, a modified version of the interview is repeated.

In Tallinn, and in it's first iteration in NYC, Break the Cycle used a pre- versus post- design to compare the proportion of participants who helped with first injections, and who promoted injecting among non-PWID, in the 6 months prior to baseline with the proportions at the 6-month follow-up. Based on previous research on the intervention and on the underlying theory of motivational interviewing, increases in helping and promoting behaviors between baseline and follow-up would indicate that the intervention was not effective regardless of their effect size. Accordingly, the hypotheses that the intervention will produce reductions in assisting with first injections and engaging in injection promoting behaviors will be evaluated using one-tailed statistical tests. Break the Cycle intervention follows a motivational interviewing approach to enhance current injectors' motivation and skills to avoid helping with and promoting first injections among non-PWID. The intervention's core is a discussion between an interventionist and each participant on the following eight topics: the participant's first time injecting drugs; the participant's exposures to situations where helping with others' first injections is an option, and the extent to which they have helped; PWIDs' behaviors that might encourage non-PWID to inject for the first time; the range of risks associated with injection drug use; role-playing scenarios in which the participant develops behaviors and scripts for avoiding or refusing requests to initiate others into injection drug use; role- playing talking with other PWID about not encouraging non-PWID to start injecting; imparting safer injection practices when helping with a first injection seems like the best option; and receiving training in and using Narcan to reverse overdoses.

In the second iteration of Break the Cycle in New York City, a second arm to the trial was added: an attentional control intervention, Bacterial Infection Prevention. The content of Bacterial Infection Prevention is representative of the infection prevention information injection drug users ought to receive, and sometimes do, when they engage with service providers, such as syringe exchange programs. Bacterial Infection Prevention does not use Motivational Interviewing principles, but is more informational/educational in nature. This intervention focuses on bacterial infection risks that accompany injection drug use, with a special focus on risk reduction, identification, and treatment of abscesses and endocarditis. Participants eligible for Break the Cycle are randomized to either receive the Break the Cycle intervention or the Bacterial Infection Prevention intervention. Enrollment in this iteration ended in March 2020, with the advent of the Covid pandemic in the United States.

The third iteration of the Break the Cycle intervention in New York City will transform the second iteration into a phone-based study in which both Break the Cycle and Bacterial Infection Prevention are delivered to participants over the telephone. Both interventions have been slightly abbreviated to adjust to phone delivery. This iteration will commence in early spring, 2021.

Inclusion Criteria:

• have injected drugs non-medically in the last 2 months
• able to provide informed consent
• age 18 or older
• able to participate in the interview and intervention in English (in New York City), Russian or Estonian (in Tallinn, Estonia)

Exclusion Criteria:

• none