reduction among injection drug users (Des Jarlais and Hopkins, 1985; Des Jarlais et al., 1985, 1988; Hopkins, 1988; Kleinman et al., 1990; Selwyn et al., 1987). They reported an expansion of the street black market of injection equipment in New York City; the demand for sterile injection equipment was strong enough to lead to a noticeable increase in the illicit sales of such devices. An important point raised by Koester is that the fear of being caught carrying needles or syringes appears to vary across cities with similar prescription and paraphernalia laws, depending on the extent to which laws are enforced. Therefore, in cities in which these laws are consistently not enforced, injection drug users may be more likely to regularly carry sterile equipment, which reduces their need to share. Koester's findings show that drug paraphernalia laws, at least in Denver, play a significant role in explaining the high-risk sharing behaviors among certain segments of the injection drug user community. In addition to Koester's ethnographic data, empirically derived descriptive data from large-scale studies provide indirect support for the negative impact of these laws on sharing behaviors (Des Jarlais and Friedman, 1992; Nelson et al., 1991) as well as on HIV seroincidence among injection drug users (Friedman et al., 1994). For example, in a natural experiment in Baltimore, Nelson et al. (1991) were able to document lower transmission rates of HIV among injection drug users who are diabetic (i.e., with unrestricted legal access to sterile needles and syringes) compared with nondiabetic injection drug users.
Recent analyses (Metzger and DePhilippis, 1994) of data from a prospective study on the efficacy of methadone treatment in Philadelphia (Metzger et al., 1991) have elucidated the relationship between the difficulty of needle acquisition among injection drug users and their rate of needle sharing and drug use. A total of 12 months after the inception of this study, 202 of the original cohort of 325 study participants reported injection drug use in the last 6 months and formed the basis of the analyses. There was no significant difference between the needle-sharing rates of subjects who reported easier needle access at the 12-month follow-up and those who did not report easier needle access. Of those who reported increased difficulty of needle acquisition, 70 percent reported sharing needles at follow-up, compared with 8 percent of the subjects who did not report greater difficulty. Finally, these researchers found that changes in difficulty of needle acquisition were not associated with either increased or decreased use of any drugs (i.e., heroin, cocaine, amphetamines, benzodiazepines, marijuana).
These studies provide some evidence that existing statutes do affect the availability of sterile needles and syringes, are related to equipment sharing, and, as a consequence, can adversely affect the rate of transmission of HIV infection.