Association of fentanyl test strip results and change in drug use behaviors: A multi-state, community-based observational study

Background: The Stay Safe Study, conducted between May and December 2023 in the United States, investigated the association between fentanyl test strip (FTS) use and risk reduction behaviors. This paper examines the association between self-reported FTS results and change in drug use behaviors. Methods: We solicited self-reported drug and FTS use among people who use drugs (PWUD), with a baseline and four weekly surveys over a 28-day observation period in three states (Kentucky, New York and Ohio). For each day participants reported drug use, they were asked types of drugs used, use of FTS, FTS results, and 12 drug use behavior changes because of the result. A generalized estimating equation approach was used to model associations between FTS results and each outcome. Results: These analyses included 541 PWUD who used FTS at least once in the observation period. Positive FTS results were associated with participants taking turns, having naloxone nearby, and using less drugs. There was a four-fold reduction in the amount of drugs used following a positive FTS result (odds ratio (OR)=4.37; 95 % CI, 3.45–5.55). This was modified by self-reported types of drugs tested, with a 20-fold reduction when testing illicit benzodiazepines (OR=19.92; 95 % CI, 8.6–46.27), a 10-fold reduction when testing illicit stimulants (OR=10.04; 95 % CI, 6.49–15.53), and 2-fold reduction in drugs used when testing illicit opioids or other drugs tested (OR=2.11; 95 % CI, 1.14–3.92). Conclusions: These findings suggest that FTS assist PWUD to immediately reduce their risks by changing drug use behaviors, including reducing the amount of drug used.