Program Overview

The Syringe Exchange in Portland, Oregon began November 1, 1989. The opening of the Exchange was delayed for two years because our insurance company refused to cover syringe exchange and threatened to withdraw coverage from our clinics and other programs if we started an exchange. Outside In operates medical and prenatal clinics and housing and emergency services programs for homeless youth.

At the time of the study, the Exchange operated out of a fixed site at Outside In. It now operates out of two fixed sites and one van.

At the time of the study, the Exchange operated 3-7 pm Monday-Friday. Clients were age 18 or over-it is illegal to give minors syringes in Oregon unless by order of a physician for an authorized use. Clients were asked to exhibit needle tracks at the first visit to ensure that only IV drug users were provided syringes. At the first visit clients were given three syringes-whether or not they brought any in. Thereafter, syringes were exchanged on a one-to-one basis. Outside In also gave out rinse water, cotton, alcohol swabs, condoms and information handouts.

Methods

Of over 1,000 participants in the Exchange, 753 (67%) were enrolled in the research component. Subjects were interviewed at three month intervals using the AIA (for intake) and AFA (for follow-up) Questionnaires designed by NIDA for use in its national survey of drug injectors. Consenting subjects were also tested for HIV and Hepatitis B antibodies at three month intervals. To encourage use of the exchange, subjects were allowed to remain anonymous, which prevented active tracking for follow-up, and thus limited follow-up at the three and six month data collection points.

Behavior of Exchange clients was examined at intake and at six months to determine the extent to which clients changed their behavior. To determine differences between a syringe exchange program and an outreach program, Exchange clients were compared with clients of the Portland NIDA-funded NADR outreach project for IV drug users. Clients of both groups were those who were still shooting up at six-month follow-up. The same questionnaires were used with both groups. Change in risk behavior over time was compared between groups.

A substudy was conducted to determine the extent to which the existence of the Exchange would lead injectors to return syringes to the Exchange rather than discarding them in public places. Prior to the opening of the Exchange, staff began to count (and collect) syringes in the vicinity on a daily basis. The data on syringes found before opening were compared to data on syringes found after the exchange opened.¹

Results

In the first two years since the Syringe Exchange began, 1,145 clients made 6,368 visits. Nearly 49,000 syringes were given out, with over 45,000 returned. The syringe return rate for the two years was 93% (see Table 1).

TABLE 1

Portland Syringe Exchange Opened November 1, 1989 after more than two years of effort.

A description of the first 700 injectors using the Exchange and participating in the study is provided in Table 2.

TABLE 2

Demographics Among 700 Drug Injectors Who Used the Exchange At Least Once.

The HIV infection rate among clients at intake was 3.9%. There was only one HIV seroconversion in 162 person-years at risk, for an HIV seroconversion rate of 0.619 per 100 person-years at risk (95% confidence intervals 0.109, 3.506). The single seroconversion was noted at the six month follow-up, so it is possible that this person may have become infected prior to beginning to use the Exchange.

The infection rate for hepatitis B core antibody at intake was much higher-54%. Thirteen subjects seroconverted in 63.3 person-years at risk, for an HBV seroconversion rate of 20.5 per 100 person-years at risk (95% confidence intervals 12.0, 35.1).

Syringe exchange clients showed a considerable reduction in risk behavior over a range of risk behaviors measured at intake and at six months. Significant and meaningful declines were reported in sharing of syringes, as well as renting works, borrowing works, and cleaning works. (See Table 3).

TABLE 3

Risk Behaviors Among 77 Portland Syringe Exchange Clients.

Of the 117 subjects for whom follow-up data were obtained at six months, 34 attended the Exchange three or fewer times, and 83 attended it four or more times. These two groups were distinguished to try to separate out clients who came in only to collect interview fees and not otherwise using the Exchange from those really using the Exchange. The frequent attenders report significantly greater risk reduction on borrowing and on throwing away used syringes. This latter result indicates that injectors are using the Exchange as intended, that is returning syringes for safe disposal rather than simply discarding them. (Table 4)

TABLE 4

Risk Behaviors Among Clients Who Used the Exchange Less than Four Times (N=32) and Clients Who Used It Four or More Times (N=83).

On the other hand, the analysis indicate that while all clients reduced drug injection frequency, frequent attenders reduced frequency of injection less than infrequent attenders. While this did not reach significance (P < .099), it is worthy of note. Further analysis is needed to determine whether this is a methodological artifact analogous to regression to the mean (since those who come to inject only rarely will have little reason to frequently attend the Exchange to get new syringes.); a result of personal characteristics of these subjects (such as the stage of their addiction); or is an unintended effect of the program.

The respondents had long histories of IV drug use; there is little evidence in our data to support the idea that syringe exchanges recruit new users. Less than 2% of our respondents had histories of injecting of less than a year. The average duration of IV drug use was 14 years, and over 75% of respondents had been injecting for 5 years or more. Those with the longest histories of injecting were likely to be the heaviest current IV drug users (p <.004).

Drug injectors using the Syringe Exchange were then compared to drug injectors not using the Exchange. Clients for the comparison group were drawn from the Portland NADR outreach project. This was not an ideal comparison group in that drug injectors in the project did receive interventions. All NADR clients received bleach and were provided with HIV education. A subset either participated in groups or received one-on-one counseling. They were also encouraged to buy and use sterile syringes (legally available over-the-counter in Oregon).

Seventy-seven Exchange clients who attended the Exchange four or more times were compared to 355 NADR clients. Demographic information for both groups is shown in Table 5.

TABLE 5

The comparison between these projects in complicated by potentially different subject populations. While there were no differences between samples on most variables, there were some differences. For example, NADR subjects were considerably more likely to be African American and less likely to be Latino; more likely to live in their own place, and were engaged in less risky injection practices at intake (e.g., they were more likely to clean syringes after use). Perhaps because we were studying frequent attenders, exchange users at six months follow up injected more frequently than the NADR subjects. These differences between samples may limit the conclusions that can be drawn from the comparison.

Subjects in both projects report significantly lower levels of risk over a wide range of risk behaviors at follow-up than at intake. On most of these measures no statistically significant differences in the amount of risk reduction were found between projects. However, syringes exchange subjects were significantly better on two variable involving risky injection behavior (Table 6): reduction in the extent to which subjects re-used syringes without cleaning-a key goal of the project, and the extent to which they no longer threw away used syringes (but returned them to the Exchange).

TABLE 6

Risk Behaviors Among 77 Portland Syringe Exchange Clients and 335 NADR Clients.

Differences are of particular significance in that syringes are legally available in Oregon, and the bleach outreach program encourages drug injectors to buy and use sterile syringes. Differences between the Exchange and the outreach program are likely smaller than they would be between an Exchange and an outreach program in a state where purchase of syringes was illegal.

Of considerable importance is the fact that syringe exchange and bleach outreach projects seem to recruit different clienteles. There was little overlap between the samples, with the Portland NADR project finding that only 11% of its sample had ever used the syringe exchange. Thus, it appears that syringe exchanges and outreach programs might best be seen as complementary strategies that recruit and produce risk reduction among different sub-populations of drug injectors, rather than as competing options that should be chosen among to find which is the best approach to HIV prevention.

The substudy on discarded syringes assessed the impact of the Syringe Exchange on the community in terms of the number of potentially infectious syringes thrown away on the streets.¹ In order to provide baseline data, a daily syringe search was begun three-and-one-half months prior to the opening of the Exchange. Discarded syringes were collected, counted and disposed of safely. Using consistent search patterns, this syringe count was continued until June 30, 1991.

Table 7 presents data comparing the number of days on which syringes were and were not found prior to and subsequent to the opening of the Exchange. Syringes were significantly more likely to be found prior to its opening (chi-square = 4.048; p < .05).

TABLE 7

Mean number of syringes found before and after Exchange opened.

In spite of the fact that syringe exchanges aim to increase the availability of (sterile) syringes for drug injectors, this exchange has not led to an increase in the number of discarded syringes with which children or others might stick themselves. Instead, it reduced the number of discarded—and possibly contaminated—syringes in the streets.

Conclusions

The data presented here support the growing body of evidence that exchanges produce behavioral risk reduction. They also provide evidence that the number of potentially infected syringes in public places can be reduced by opening syringe exchanges. Comparisons between Exchange subjects and NADR are preliminary, with further analyses needed to control for possible differences between samples. Syringe exchange and bleach outreach programs are best seen as strategies that complement each other. They recruit different populations of drug injectors, and both lead to risk reduction. Differences between programs are likely smaller than in a city where syringes were illegal and the bleach outreach programs could not encourage people to buy sterile syringes.

These data are of course not definitive evidence that syringe exchanges reduce the spread of HIV or other pathogens. Indeed, it is not likely that a truly definitive study can ever be conducted of syringe exchanges, any more than this is feasible with evaluations of drug abuse treatment, drug interdiction, or laws against drug use. The cumulative weight of the research, however, and the fact that no studies have found any indication that the exchanges are doing any damage, clearly puts the burden of proof on opponents of syringe exchanges. In the interim, given the dangers from HIV spread, syringe exchanges should become an important part of the public health response to AIDS.

Acknowledgments

We would like to acknowledge the support by the American Foundation for AIDS Research and the Multnomah County Health Division.

We would also like to acknowledge the staff of Outside In and the volunteers from Portland State University and the Portland community who assisted in making the Portland, Oregon syringe exchange and this research possible.

Reference

1.

Oliver KJ, Friedman SR, Maynard H, Magnuson LJ, Des Jarlais DC. Impact of needle exchange program on potentially infectious syringes in public places. JAIDS . 1992; 5:534-535. [PubMed: 1560355]