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An external evaluation of a peer-run outreach-based syringe exchange in Vancouver, Canada Hayashi, Kanna; Wood, Evan; Wiebe, Lee; Qi, Jiezhi; Kerr, Thomas Sep 30, 2010

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An external evaluation of a peer-run outreach-based syringeexchange in Vancouver, CanadaKanna Hayashi1,2, Evan Wood1,3, Lee Wiebe4, Jiezhi Qi1, and Thomas Kerr1,3Kanna Hayashi: kanna.hayashi@gmail.com; Evan Wood: uhri-ew@cfenet.ubc.ca; Lee Wiebe: stayoutin@yahoo.ca; JiezhiQi: jqi@cfenet.ubc.ca; Thomas Kerr: uhri-tk@cfenet.ubc.ca1 British Columbia Centre for Excellence in HIV/AIDS, St. Paul’s Hospital, Vancouver, Canada2 Interdisciplinary Studies Graduate Program, University of British Columbia, Vancouver, Canada3 Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver,Canada4 Vancouver Area Network of Drug Users, Vancouver, CanadaAbstractObjective—Vancouver, Canada has been the site of an epidemic of human immunodeficiencyvirus (HIV) among injection drug users (IDU). In response, the Vancouver Area Network of DrugUsers (VANDU) initiated a peer-run outreach-based syringe exchange programme (SEP) calledthe Alley Patrol. We conducted an external evaluation of this programme, using data obtainedfrom the Vancouver Injection Drug Users Study (VIDUS).Methods—Using generalised estimating equations (GEE) we examined the prevalence andcorrelates of use of the SEP among VIDUS participants followed from 1 December 2000 to 30November 2003.Results—Of 854 IDU, 233 (27.3%) participants reported use of the SEP during the study period.In multivariate GEE analyses, service use was positively associated with living in unstablehousing (Adjusted Odds Ratio [AOR] = 1.83, 95% Confidence Interval [CI]: 1.39 – 2.40), dailyheroin injection (AOR = 1.31, 95% CI: 1.01 – 1.70), daily cocaine injection (AOR = 1.34, 95%CI: 1.03 – 1.73), injecting in public (AOR = 3.07, 95% CI: 2.32 – 4.06), and negatively associatedwith needle reuse (AOR = 0.65, 95% CI: 0.46 – 0.92).Conclusion—The VANDU Alley Patrol SEP succeeded in reaching a group of IDU atheightened risk for adverse health outcomes. Importantly, access to this service was associatedwith lower levels of needle reuse. This form of peer-based SEP may extend the reach of HIVprevention programmes by contacting IDU traditionally underserved by conventional syringeexchange programmes.Keywordsinjection drug use; syringe exchange; harm reduction; peer-driven approach; VancouverSend correspondence to: Thomas Kerr, PhD, BC Centre for Excellence in HIV/AIDS, 608 - 1081 Burrard Street, Vancouver BC V6Z1Y6, Canada, Fax: 604 806 9044, uhri-tk@cfenet.ubc.ca.Conflict of Interests: None.Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to ourcustomers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review ofthe resulting proof before it is published in its final citable form. Please note that during the production process errors may bediscovered which could affect the content, and all legal disclaimers that apply to the journal pertain.NIH Public AccessAuthor ManuscriptInt J Drug Policy. Author manuscript; available in PMC 2011 September 1.Published in final edited form as:Int J Drug Policy. 2010 September ; 21(5): 418–421. doi:10.1016/j.drugpo.2010.03.002.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptINTRODUCTIONHuman immunodeficiency virus (HIV) epidemics among people who inject drugs (IDU)remain a challenge globally (Mathers et al., 2008; UNAIDS, 2008). Although variousevidence-based HIV prevention programmes for this population exist, (Farrell, Gowing,Marsden, Ling, & Ali, 2005; Needle et al., 2005; Wodak & Cooney, 2006), only 8% of IDUworldwide have access to HIV prevention initiatives (The Global HIV Prevention WorkingGroup, 2007).While a growing body of research demonstrates the effectiveness of HIV prevention serviceprovision through peer-based outreach (Broadhead, Heckathorn, Grund, Stern, & Anthony,1995; Broadhead et al., 1998; Grund et al., 1992; Latkin, 1998; Needle et al., 2005), theimpact and reach of “drug user-initiated” HIV prevention programmes are seldom evaluated,primarily because such grass-root activities rarely incorporate rigorous evaluation activities(Friedman et al., 2007). Fortunately, in Vancouver, Canada, the existence of a prospectivecohort study of IDU enabled us to conduct an external evaluation of a peer-run outreach-based syringe exchange programme (SEP) initiated by the Vancouver Area Network ofDrug Users (VANDU), a local drug user organisation.VANDU Alley Patrol Syringe Exchange ProgrammeIn the 1990s, Vancouver had an epidemic of HIV among IDU despite the presence of one ofthe largest SEPs in North America (Strathdee, Patrick, Currie et al., 1997). In autumn 2000,VANDU established the Alley Patrol, a novel peer-based outreach programme, designed toaddress gaps in conventional public health services by providing education on subjects suchas HIV prevention as well as the means to prevent harm among those who used drugs inpublic spaces (Kerr et al., 2006). Approximately 20 trained volunteers paired up anddistributed sterile injection equipment and condoms, collected used syringes, and providedharm reduction education to IDU in public places in Vancouver’s Downtown Eastside,where public drug use was concentrated. Each pair worked 4-hour shifts and received asmall volunteer stipend ($20 CAD). Depending on funding, their patrol shifts ranged fromtwo to five days a week during days or nights. The volunteers experienced many challengeswhile providing this support, such as finding IDU displaced during police crackdowns(Csete & Cohen, 2003; Eby, 2006). The programme ended in 2005, but several memberslater created the Injection Support Team. This provides support to IDU experiencingdifficulty with injecting in the open drug scene.METHODSData for this study were obtained from the Vancouver Injection Drug Users Study (VIDUS),an ongoing prospective cohort study of IDU recruited through self-referrals and streetoutreach since May 1996 (Tyndall et al., 2003; Wood et al., 2001). Eligibility criteria forparticipation include injecting drugs a minimum of once in the previous month, residing inthe greater Vancouver region and providing written informed consent. Participants completean interviewer-administered questionnaire and provide a blood sample at semi-annualfollow-up visits so that drug use, HIV risk behaviour, and HIV incidence can be trackedlongitudinally. The study has been approved by St. Paul’s Hospital and the University ofBritish Columbia’s Research Ethics Board. As the VANDU established the Alley Patrolprogramme, the VIDUS questionnaire was modified to examine whether study participantswere obtaining syringes from Alley Patrol volunteers.The present analyses included data from participants who completed follow-up visitsbetween 1 December 2000 and 30 November 2003 and who reported having injected drugsduring six months prior to their visits. The study period ending in November 2003 wasHayashi et al. Page 2Int J Drug Policy. Author manuscript; available in PMC 2011 September 1.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author Manuscriptchosen because after autunm of 2003, SEPs in Vancouver were radically changed by theopening of the supervised injection facility (Kerr, Tyndall, Li, Montaner, & Wood, 2005).The primary outcome of interest was the use of the VANDU Alley Patrol SEP during sixmonths prior to the interviews. Explanatory variables were selected with the aim ofevaluating the vulnerability of Alley Patrol SEP users to HIV infection and other forms ofdrug-related harm, and to evaluate potential impacts of the Alley Patrol SEP. These includedage (continuous), gender, Aboriginal ancestry and HIV sero-status, as well as other relevantbehaviours and activities during the previous six months: unstable housing; sex work; dailyheroin and cocaine injection; injecting in public; injecting with others; requiring helpinjecting; having difficulty accessing sterile syringes; borrowing syringes; average needlereuse (>once vs. once); syringe disposal (unsafe vs. safe); and non-fatal overdose. Allvariables were coded dichotomously as yes or no, unless otherwise stated. Variabledefinitions were identical to earlier reports (DeBeck et al., 2009; Wood et al., 2003b).First, we examined the rates of the VANDU Alley Patrol SEP use throughout the studyperiod. The rate was derived as the proportion of individuals who accessed the SEP during a6-month period over all individuals followed during that period. Next, we examinedunivariate associations between the explanatory variables and the use of the Alley PatrolSEP. Since the variables used for the analyses included serial measures for each subject, weused generalised estimating equations (GEE) (Lee, Herzog, Meade, Webb, & Brandon,2007). We then applied an a priori-defined statistical protocol that examined factorsassociated with the use of the SEP. This was done by fitting a GEE multivariate logisticregression model that included all variables that were significantly associated with the use ofthe SEP at the p < 0.05 level in univariate analyses. All p-values were two-sided.RESULTSIn total, 854 IDU were eligible for this analysis, including 350 (41.0%) females and 292(34.2%) individuals of Aboriginal ancestry. The median age at baseline was 37.4 years(interquartile range (IQR): 29.2 – 44.2 years). In total, 233 (27.3%) participants reportedobtaining syringes from VANDU Alley Patrol volunteers at some point during the studyperiod. As shown in Figure 1, the proportions of IDU who accessed the Alley Patrol SEPsteadily increased during the study period.Table 1 presents the results of the univariate and multivariate GEE analyses of factorsassociated with the self-reported use of the SEP. In the multivariate GEE analyses, serviceuse was associated with unstable housing (Adjusted Odds Ratio [AOR] = 1.83, 95% CI: 1.39– 2.40), frequent heroin injection (AOR = 1.31, 95% CI: 1.01 – 1.70), frequent cocaineinjection (AOR = 1.34, 95% CI: 1.03 – 1.73), injecting in public (AOR = 3.07, 95% CI: 2.32– 4.06), and needle reuse (AOR = 0.65, 95% CI: 0.46 – 0.92).DISCUSSIONConsistent with previous studies of peer-based outreach HIV prevention programmes forIDU (Broadhead et al., 1998; Grund et al., 1992; Needle et al., 2005), our findings indicatethat the VANDU Alley Patrol SEP succeeded in reaching a sub-population of local IDU at ahigh risk of HIV infection. Specifically, frequent cocaine injection has been shown to bestrongly associated with HIV sero-conversion among IDU in Vancouver (Tyndall et al.,2003). Previous studies have also demonstrated that unstable housing (Corneil et al., 2006)and public injecting (DeBeck et al., 2009) are associated with elevated HIV risk in thissetting. Of note is that the Alley Patrol SEP continued to serve this highly vulnerablepopulation during periodic police crackdowns in Vancouver’s Downtown Eastside (Eby,2006). These crackdowns have been shown to have significantly decreased access to otherHayashi et al. Page 3Int J Drug Policy. Author manuscript; available in PMC 2011 September 1.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author Manuscriptlocal fixed-site SEPs (Csete & Cohen, 2003; Small, Kerr, Charette, Schechter, & Spittal,2006; Wood et al., 2003a; Wood et al., 2004). The findings indicate further value of theAlley Patrol SEP in providing the equipment and support needed to reduce risks associatedwith unsafe injection practices.Importantly, needle reuse was independently and negatively associated with the use of theVANDU Alley Patrol SEP, despite the fact that the IDU served by the SEP possessedseveral characteristics, such as unstable housing and frequent cocaine injection, that canincrease the likelihood of needle reuse (Corneil et al., 2006; Strathdee, Patrick, Archibald etal., 1997; Wood et al., 2002; Wood et al., 2001). The Alley Patrol SEP, therefore, may havesucceeded in reducing needle reuse among local IDU.Our study has several limitations. We cannot infer causation from this observational study.Since VIDUS is not a random sample, our study findings may not be generalisable to otherpopulations of IDU in Vancouver or other settings. The self-reported data may be affectedby socially desirable reporting. However, since the participants and interviewers wereblinded to the eventual use of the data, we believe it unlikely that socially desirableresponding affected our findings. Lastly, it is unknown whether Alley Patrol SEP userswould have simply used other SEPs in the local area if the Alley Patrol did not exist.In sum, we found that the VANDU Alley Patrol SEP succeeded in reaching IDU atheightened risk for adverse health outcomes. Importantly, access to this service wasassociated with lower levels of needle reuse. These findings point to the important role thatdrug user-led initiatives can play in extending the reach of conventional public healthprogrammes.AcknowledgmentsThe authors would particularly like to thank the VIDUS participants for their contribution to the research, as well ascurrent and past researchers and staff. The authors would also like to thank Deborah Graham, Tricia Collingham,Caitlin Johnston, Steve Kain, and Calvin Lai for their research and administrative assistance. The study wassupported by the US National Institutes of Health (R01DA011591-04A1) and the Canadian Institutes of HealthResearch (MOP-67262). TK is supported by the Michael Smith Foundation for Health Research and the CanadianInstitutes of Health Research. KH is supported by a University of British Columbia Doctoral Fellowship.ReferencesBroadhead RS, Heckathorn DD, Grund JPC, Stern LS, Anthony DL. Drug users versus outreachworkers in combating AIDS: preliminary results of a peer-driven intervention. Journal of DrugIssues 1995;25(3):531–564.Broadhead RS, Heckathorn DD, Weakliem DL, Anthony DL, Madray H, Mills RJ, et al. Harnessingpeer networks as an instrument for AIDS prevention: results from a peer-driven intervention. PublicHealth Rep 1998;113(Suppl 1):42–57. [PubMed: 9722809]Corneil TA, Kuyper LM, Shoveller J, Hogg RS, Li K, Spittal PM, et al. Unstable housing, associatedrisk behaviour, and increased risk for HIV infection among injection drug users. Health Place2006;12(1):79–85. [PubMed: 16243682]Csete, J.; Cohen, J. A busing the user: police misconduct, harm reduction and HIV/A IDS inVancouver. New York: Human Rights Watch; 2003.DeBeck K, Small W, Wood E, Li K, Montaner J, Kerr T. Public injecting among a cohort of injectingdrug users in Vancouver, Canada. J Epidemiol Community Health 2009;63(1):81–86. [PubMed:18628270]Eby D. The political power of police and crackdowns: Vancouver’s example. International Journal ofDrug Policy 2006;17(2):96–100.Farrell M, Gowing L, Marsden J, Ling W, Ali R. Effectiveness of drug dependence treatment in HIVprevention. International Journal of Drug Policy 2005;16(Supplement 1):67–75.Hayashi et al. Page 4Int J Drug Policy. Author manuscript; available in PMC 2011 September 1.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptFriedman SR, de Jong W, Rossi D, Touze G, Rockwell R, Des Jarlais DC, et al. Harm reductiontheory: Users’ culture, micro-social indigenous harm reduction, and the self-organization andoutside-organizing of users’ groups. International Journal of Drug Policy 2007;18(2):107–117.[PubMed: 17689353]Grund JP, Blanken P, Adriaans NF, Kaplan CD, Barendregt C, Meeuwsen M. Reaching the unreached:targeting hidden IDU populations with clean need les via known user groups. J Psychoactive Drugs1992;24(1):41–47. [PubMed: 1619521]Kerr T, Small W, Peeace W, Douglas D, Pierre A, Wood E. Harm reduction by a “user-run”organization: A case study of the Vancouver Area Network of Drug Users (VAN DU).International Journal of Drug Policy 2006;17(2):61–69.Kerr T, Tyndall M, Li K, Montaner J, Wood E. Safer injection facility use and syringe sharing ininjection drug users. Lancet 2005;366(9482):316–318. [PubMed: 16039335]Latkin CA. Outreach in natural settings: the use of peer leaders for HIV prevention among injectingdrug users’ networks. Public Health Rep 1998;113(Suppl 1):151–159. [PubMed: 9722820]Lee JH, Herzog TA, Mead e CD, Webb MS, Brandon TH. The use of GEE for analyzing longitudinalbinomial data: a primer using data from a tobacco intervention. Addict Behav 2007;32(1):187–193. [PubMed: 16650625]Mathers BM, Degenhardt L, Phillips B, Wiessing L, Hickman M, Strathdee SA, et al. Globalepidemiology of injecting drug use and HIV among people who inject drugs: a systematic review.The Lancet 2008;372(9651):1733–1745.Needle RH, Burrows D, Friedman SR, Dorabjee J, TouzÈ G, Badrieva L, et al. Effectiveness ofcommunity-based outreach in preventing HIV/AIDS among injecting drug users. InternationalJournal of Drug Policy 2005;16(Supplement 1):45–57.Small W, Kerr T, Charette J, Schechter MT, Spittal PM. Impacts of intensified police activity oninjection drug users: Evidence from an ethnographic investigation. International Journal of DrugPolicy 2006;17(2):85–95.Strathdee SA, Patrick DM, Archibald CP, Ofner M, Cornelisse PG, Rekart M, et al. Socialdeterminants predict needle-sharing behaviour among injection drug users in Vancouver, Canada.Addiction 1997;92(10):1339–1347. [PubMed: 9489050]Strathdee SA, Patrick DM, Currie SL, Cornelisse PG, Rekart ML, Montaner JS, et al. Needle exchangeis not enough: lessons from the Vancouver injecting drug use study. AIDS 1997;11(8):F59–65.[PubMed: 9223727]The Global HIV Prevention Working Group. Bringing HIV prevention to scale: an urgent globalpriority. 2007. Retrieved November 12, 2009, fromhttp://www.globalhivprevention.org/pdfs/PWG-HIV_prevention_report_FINAL.pdfTyndall MW, Currie S, Spittal P, Li K, Wood E, O’Shaughnessy MV, et al. Intensive injection cocaineuse as the primary risk factor in the Vancouver HIV-1 epidemic. AIDS 2003;17(6):887–893.[PubMed: 12660536]UNAIDS. Report on the global AIDS epidemic. Geneva: Joint United Nations Programme on HIV/AIDS (UNAIDS); 2008.Wodak A, Cooney A. Do needle syringe programs reduce HIV infection among injecting drug users: acomprehensive review of the international evidence. Subst Use Misuse 2006;41(6–7):777–813.[PubMed: 16809167]Wood E, Kerr T, Small W, Jones J, Schechter MT, Tyndall MW. The impact of a police presence onaccess to needle exchange programs. J Acquir Immune Defic Syndr 2003a;34(1):116–118.[PubMed: 14501805]Wood E, Kerr T, Spittal PM, Small W, Tyndall MW, O’Shaughnessy MV, et al. An externalevaluation of a peer-run “unsanctioned” syringe exchange program. Journal of Urban Health2003b;80(3):455–464. [PubMed: 12930883]Wood E, Spittal PM, Small W, Kerr T, Li K, Hogg RS, et al. Displacement of Canada’s largest publicillicit drug market in response to a police crackdown. CMAJ 2004;170(10):1551–1556. [PubMed:15136548]Hayashi et al. Page 5Int J Drug Policy. Author manuscript; available in PMC 2011 September 1.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptWood E, Tyndall MW, Spittal PM, Li K, Hogg RS, Montaner JS, et al. Factors associated withpersistent high -risk syringe sharing in the presence of an established needle exchange programme.AIDS 2002;16(6):941–943. [PubMed: 11919503]Wood E, Tyndall MW, Spittal PM, Li K, Kerr T, Hogg RS, et al. Unsafe injection practices in a cohortof injection drug users in Vancouver: could safer injecting rooms help? CMAJ 2001;165(4):405–410. [PubMed: 11531048]Hayashi et al. Page 6Int J Drug Policy. Author manuscript; available in PMC 2011 September 1.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptFigure 1.Rates of self-reported use of the VANDU Alley Patrol SEP among active injection drugusers in Vancouver, Canada (December 2000 - November 2003)Hayashi et al. Page 7Int J Drug Policy. Author manuscript; available in PMC 2011 September 1.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptHayashi et al. Page 8Table 1Univariate and multivariate GEE analyses of factors associated with accessing the VANDU Alley Patrolsyringe exchange among a cohort of active injection drug users in Vancouver, Canada (study period December2000 – November 2003; n = 854)Unadjusted AdjustedCharacteristic Odds Ratio (95% CI) p - value Odds Ratio (95% CI) P – valueOlder age (per year older) 0.97 (0.95 – 0.98) <0.001 1.00 (0.98 – 1.01) 0.681Gender (male vs. female) 0.79 (0.59 – 1.04) 0.095Aboriginal ancestry (yes vs. no) 1.40 (1.05 – 1.86) 0.022 1.24 (0.95 – 1.63) 0.113HIV positivity (yes vs. no) 1.23 (0.92 – 1.64) 0.155Unstable housing*† (yes vs. no) 2.04 (1.56 – 2.66) <0.001 1.83 (1.39 – 2.40) <0.001Sex work* (yes vs. no) 1.71 (1.24 – 2.34) <0.001 1.26 (0.91 – 1.74) 0.162Heroin injection frequency* (≥1 per day vs. <1 per day) 1.94 (1.51 – 2.49) <0.001 1.31 (1.01 – 1.70) 0.039Cocaine injection frequency* ((≥1 per day vs. <1 per day) 1.69 (1.31 – 2.18) <0.001 1.34 (1.03 – 1.73) 0.029Injected in public*§ (yes vs. no) 3.47 (2.66 – 4.53) <0.001 3.07 (2.32 – 4.06) <0.001Injected with others*# (yes vs. no) 1.28 (0.96 – 1.70) 0.089Required help injecting* (yes vs. no) 1.50 (1.17 – 1.93) 0.001 1.30 (1.00 – 1.68) 0.050Difficulty accessing syringes* (yes vs. no) 1.27 (0.96 – 1.66) 0.092Borrowed syringe* (yes vs. no) 1.04 (0.73 – 1.47) 0.836Average needle reuse* (>1 vs. 1) 0.67 (0.48 – 0.94) 0.020 0.65 (0.46 – 0.92) 0.016Syringe disposal* (unsafe vs. safe)** 0.71 (0.51 – 0.97) 0.034 0.75 (0.54 – 1.04) 0.080Non-fatal overdose* (yes vs. no) 1.37 (0.88 – 2.14) 0.163GEE, generalized estimating equations; VANDU, Vancouver Area Network of Drug Users; CI, confidence interval.*denotes activities/events in the previous six months.†refers to living in a single room occupancy hotel, transitional living arrangements, or homelessness.§refers to bars, restaurants, parks, streets, public washrooms, parking lots, abandoned buildings, or other public settings.#refers to injecting drugs with somebody at least once in the previous six months.**Unsafe disposal refers to “threw it in the garbage or on the ground,” “gave it to another user,” or “flushed it down the toilet.” Safe disposal refersto “put it in: sharps containers, a safe place, syringe exchange, clinics or the Contact Centre.”Int J Drug Policy. Author manuscript; available in PMC 2011 September 1.


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