Syringe Service Program Use and Substance Use Treatment

"In this study, there was no indication that needle-exchange use was associated with increasing drug use. Indeed, IDUs who were former users of the exchange were more likely than never-users to report substantial reductions in drug use or stopping injection altogether. Our analysis also suggested that among heroin injectors, needle-exchange participation was wholly compatible with the goals of drug treatment. Compared to those who had never used an exchange, new exchange users were five times more likely to enter methadone treatment and ex-exchangers were 60% more likely to remain in methadone treatment over the 1-year study period.

"Many factors may influence drug injection frequency in a population, including cost and availability of different drugs and access to drug treatment (Frykholm & Gunne 1980, Nurco et al. 1981, Robins 1980). The natural history of drug injection is also characterized by a progression toward daily use (Robins 1980). The ability of an exchange program to override these underlying factors is not well-understood, however, there is a well-recognized motivation to reduce or cease drug use exhibited by some users (Koester et al. 1999). It is conceivable that exposure to needle exchange could accelerate or facilitate this process by offering encouragement and support for risk reduction and improved self-care, and as a conduit to drug treatment services.

"In this study, baseline rate of injection was an important determinant of subsequent change in injection frequency. In all subject categories, most subjects who initially reported fewer than one injection per day progressed to daily injection by the end of the follow-up period. In contrast, reduction in drug use was more common among those who were daily injectors at the baseline visit. Since it was a potential confounder, we examined the association between needle exchange and reduction in injection, adjusted for baseline injection frequency and within separate strata of daily and nondaily injectors. This method of analysis would tend to reduce the influence of regression to the mean on our results. Further, we found that the group with the highest proportion of subjects reporting reduction in injection frequency (ex-exchangers) reported a relatively lower mean number of injections at study enrollment. Thus, it was unlikely that regression to the mean was responsible for the observed association."