Diversion of methadone and buprenorphine by patients in opioid substitution treatment in Sweden: prevalence estimates and risk factors

Abstract

Background: Diversion--patients who sell or share their medication--is a hotly debated but relatively unresearched phenomenon. We have investigated the prevalence of self-reported diversion of methadone and buprenorphine at OST programs in Sweden. We have also examined if demographic, treatment, and social factors can be associated with an increased risk of diversion.

Methods: Structured interviews were conducted with 411 patients from eleven OST programs. A standardized questionnaire with 106 close- and five open-ended questions were used. 280 interviews were done on site, by the researchers, while 131 interviews were conducted by specially trained patients through privileged access interviewing. The data were analyzed through frequency- and averages-calculations, cross-tabulations, and logistic regression analysis.

Results: In total, 24.1% (n=99) of the patients reported diversion in the past month. 67.6% (n=277) stated that they had diverted at some point. The peer interviews showed significantly higher levels of diversion (37.4% past month) compared with the researcher interviews (17.2%). Neither demographic factors, dosages, nor collection routines were associated with diversion. The likelihood of diversion was higher for patients on mono-buprenorphine (OR=5.64) and buprenorphine-naloxone (OR=2.10), than among methadone patients. Other factors which increased the likelihood of diversion were current illicit drug use (OR=5.60), having had patients as a primary source of illicit methadone or buprenorphine prior to treatment (OR=3.39), and mainly socializing with active drug users (OR=2.12).

Conclusion: Self-reported diversion was considerably higher than in previous studies. This is most likely due to the new methodological strategy we used, but may also partly be explained by low availability of OST in Sweden, leading to a high demand for the substances by heroin users outside treatment. Efforts to decrease diversion should primarily focus on psychosocial and lifestyle-changing interventions, and expanded access to treatment, rather than on control measures.

Keywords: Buprenorphine; Diversion; Illicit use; Methadone; Opioid substitution treatment.