Introduction

Several criteria can theoretically be used to evaluate the success of needle exchange programmes. Among them are measures of awareness of the service in the target population of injection drug users (IDU), utilization rates, and satisfaction with the overall service among the clientele. Changes in injecting behaviour can be documented cross-sectionally or, better yet, followed over time in a cohort of IDU to provide a measure of the behavioural impact of prevention-education activities in the injecting drug using population. Once a baseline HIV prevalence proportions has been established, it can be followed prospectively to assess the stability of prevalence and document any increases or declines. The gold standard criterion for success, which has appears to have achieved general consensus, is the estimation of baseline HIV incidence with subsequent documented declines in incidence among injection drug users who are attending a needle exchange programme regularly.

From a more general perspective, the implementation and maintenance of needle exchange activities should ideally have positive influences on policy and programme development, both at the local and national level. Since the opening of CACTUS-Montréal (Centre dAction Communautaire auprès des Toxicomanes Utilisateurs de Seringues), there have been eight other projects initiated across the province of Québec in both urban and semi-urban settings. Among them is a project for pharmacy exchange currently in the pilot phase in Montréal and two projects involving community clinic and hospital-based exchange services in semi-urban areas. Finally, needle exchange programmes are perceived to have the potential to increase demand for methadone maintenance, detoxification services and rehabilitation programmes and therefore should result in expansion of these services although such an expansion has not been documented thus far in Québec.

The CACTUS-Montréal fixed site is located at 1209 Saint-Dominique Street in downtown Montréal. It has been operating seven nights a week from 21:15 to 04:00 since July 9, 1989. Clients enter the site directly from the street. There is no exterior sign identifying the building as a needle-exchange site other than several cactus plants in the window. Two teams, each composed of a male and female nurse, alternate to provide seven day coverage. In addition to disseminating information on AIDS and the prevention of HIV transmission, the nurses distribute condoms, alcohol swabs, lubricant, gloves and travel size bottles containing bleach or distilled water. They also exchange sterile needles and syringes for used ones. First time clients receive a pamphlet which demonstrates how to clean needles and how to use condoms. Additional print materials regarding AIDS and other STD as well as business cards which indicate resources and the range of treatment options available in Montréal for drug users are available on site. Anonymous testing for HIV antibodies accompanied by pre and post-test counselling is also offered at scheduled times in a closed private room.

The exchange policy is a one-for-one exchange to a maximum of 15 needles with one extra needle always provided. Individuals who arrive with no needle are provided with one needle with no examination for needle tracks. The exchange rate has averaged a relatively stable rate of 75-80% over the period 1991 to 1993. The total number of visits per week stabilized by one year of operation at approximately 1200 visits per week.

Two components of the CACTUS-Montréal evaluation will be discussed in this paper. The first concerns the findings of the awareness, utilization, and satisfaction study conducted in the first two years of operation and the second concerns data from the prevalence-incidence study underway at the CACTUS-Montréal fixed site.

Awareness, Utilisation, Satisfaction

To determine the degree of awareness, utilisation, and satisfaction with the services offered at the exchange's fixed site, injection drug using CACTUS-Montréal attenders were approached in three correctional medium security institutions and at a detox unit drop-in clinic for individual interviews of five to ten minutes duration¹ . Injection drug users from the correctional setting were study volunteers for an ongoing research project on risk factors for HIV infection among inmates in medium security correctional institutions² . This study involved a standardized nurse-administered interview, as well as personalized counselling and HIV antibody testing³ . At the drop-in clinic the first five IDU presenting to the clinic per week were asked to participate. A preliminary plan to administer the questionnaire at the fixed site was abandoned because the physical setting was inappropriate and because the validity of data collected in the presence of service providers was questionable.

Most information (70%) concerning levels of awareness, utilisation, and satisfaction with the services offered at the CACTUS-Montréal fixed site was obtained from incarcerated IDU, the remainder being provided by IDU attending the detox unit drop-in clinic near the fixed site. Comparing the prison subjects with the detox clinic clients, a greater proportion of women (p=.001), exclusive cocaine users (p=.0005), and people who had attended CACTUS-Montréal more than 15 times (p=.03) were represented among prison subjects. Overall, seventy-three per cent (73%) of those interviewed had heard about CACTUS-Montréal and respondents readily identified that needle-exchange services and free condoms were available at CACTUS-Montréal. Publicity for the fixed site mainly occurred by word of mouth, with 57% of aware respondents having heard about the programme from another IDU. Fifty-five per cent (55%) of those who were aware of the existence of CACTUS-Montréal had visited the fixed site, and 76% of these had actually been to CACTUS-Montréal more than five times. Attenders generally expressed satisfaction with the fixed site personnel (88% liked the staff) and 98% of attending IDU indicated that they had received the services they asked for when they visited the site. Location and opening hours did not appear to suit everyone however. When asked what they liked about CACTUS-Montréal, the most frequent responses were ''the staff" and "it's free." None of the respondents suggested that CACTUS-Montréal dispense or exchange more needles than current quotas.

Within the context of a seroepidemiological study conducted in the three correctional institutions, an analysis of seroprevalence levels in injection drug users by attender or non-attender status was conducted. One hundred and sixty-three (163) men and 130 women participated in the study. Among male injection drug users, 8.6% (14/163) were seropositive with a marked discrepancy noted between rates in attenders and non-attenders. Among male attenders of CACTUS-Montréal, 20.5% (8/29) were positive versus 4.8% (6/124) of non-attenders (p=0.002). This contrast was not observed among the 130 women, 15 of whom were seropositive (11.5%). The rate among female attenders was 11.6% (8/69) and among non-attenders it was 11.5% (7/61). Comparing all attenders and non-attenders, attenders were twice as likely to be HIV-positive with 14.8% of attenders (16/108) and 7% of non-attenders (13/185) found to be infected (p=0.05). With respect to the behavioural profiles of male inmates, attenders (n=39) and non-attenders (n = 126) were equally likely in the six months prior to incarceration to have injected with a syringe from a dealer (p=0.24) and to have given, shared or sold a used syringe to close friends (p= 0.23) or to people in shooting galleries (p=0.97). In prison, attenders and non-attenders were equally likely to have injected drugs (p= 0.35). However, attenders were significantly more likely to have had bleach in their possession (p < 0.0005) and to have injected with a needle from someone they did not know well (p=0.001). This preliminary analysis suggests that CACTUS-Montréal may be attracting a particularly high risk population, at least with respect to male participants.

HIV Antibody Seroprevalence and Seroincidence

Volunteers were enlisted at the fixed site of CACTUS-Montréal to provide anonymous samples for HIV antibody detection. On one randomly chosen evening per week during a three-hour period IDU were approached as they were leaving the site and asked to provide a blood specimen obtained via fingerprick or a saliva specimen collected in a sputum collector or Omni-sal. The sensitivity of saliva testing using the dried blood spot testing as a gold standard was 92.7% with a specificity of 100%⁴ . Since no false positive results were detected, data from individuals with only saliva specimens were combined with data from individuals with dried blood spot specimen results for analysis. Filter paper and saliva specimens were identified by a random bar code number, ensuring complete anonymity for all samples at the laboratory. This code was also affixed to a service delivery/behavioural form to permit the linkage of serology results to information concerning behaviours in the previous 7 days as well as to basic information on age and sex found in the CACTUS-Montréal client code. Such a link allowed for the characterization of participants and refusers and served to identify repeat samples for the estimation of overall seroprevalence and seroincidence. No information was collected which could be used to personally identify any one individual. Participants who desired knowledge of their HIV status were referred to clinical testing services at CACTUS-Montréal or at anonymous testing sites.

Overall, 25% of individuals who were approached agreed to provide a specimen. Most refusers seemed to refuse because they were in a hurry. Seroprevalence data were culled by year so that each person was represented only once per twelve month period. Individuals who had never obtained or returned needles and who had never responded to questions concerning injection drug use practices were excluded from the analysis.

Analyses for the period January 1990 to January 1993 yielded the following seroprevalence proportions:

Using the CACTUS-Montréal client code, repeat tests on the same individual were identified to assess seroconversions and to calculate estimates of incidence for the same 36 month period. The date of seroconversion was calculated as the mid-point between the last negative and first positive result. Incidence was calculated as a proportion (%) and as a rate in person-years (incidence density).

In 36,805 person-days of observation, 13 of 136 (9.6%) individuals, for whom at least two test results were available, seroconverted. The overall incidence rate was 12.9 per 100 person-years of observation (95% CI: 6.9; 22.0). Preliminary analyses revealed that factors such as age, gender, cocaine use, condom use, and the sexual orientation of males were not significantly associated with seroconversion. Among those who had borrowed needles in the previous seven days, the incidence rate was 18.7 per 100 person-years versus 2.5 for those who had not (p =.02). Likewise, among those who had loaned needles in the previous seven days, the incidence rate was 20.3 per 100 person-years versus 2.2 for those who had not (p=.01). Further analyses are being conducted to examine these and other sociodemographic and behavioral factors which may be associated with seronconversion and higher incidence rates.

Conclusion

The challenge in evaluating any prevention programme lies in the attempt to determine direct programme effect by measuring the gap between what would have likely happened had there been no programme and what actually has occurred in terms of behaviour change and seroprevalence/seroincidence. With respect to CACTUS-Montréal, this challenge is heightened by the finding that the programme, which has a greater than 2 to 1 ratio of male to female attenders, appears to be attracting a higher risk male clientele. This may account for the fact that prevalence has not yet completely stabilized in this population and that incidence rates remain unacceptably high. However, findings from behavioural studies at CACTUS-Montréal⁵ have revealed that the loaning of needles has declined from 31% to 20% since the beginning of operation and that 62% of those who inject with a used needle do so after having cleaned with bleach, in combination with another method or alone, compared with 30% in the first two months of operation.⁶ This suggests that this core group of injection drug users may possibly be contributing less now to HIV transmission among injection drug users that they were two years ago. The fact that these individuals are attracted to the site and are participating in risk reduction activities should be viewed as having positive implications for the eventual reduction of HIV transmission in Montréal's injection drug using community.

Acknowledgment

This study was supported by grant #6605-3463-AIDS from the National Health Research and Development Program, Department of Health, Canada.

Figure

CONSUMER AWARENESS, UTILIZATION, AND SATISFACTION WITH CACTUS-MONTRÉAL'S NEEDLE EXCHANGE Hankins Catherine A,^* Gendron S,^* Bruneau J,^** Rouah F,^* Paquette N, ^* Jalbert M,^* Prévost F,^** Gomez B,^{* *}Centre for AIDS Studies, DCS-Montreal General (more...)

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