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Gender differences in the provision of injection initiation assistance: a comparison of three North American… Meyers, Stephanie A; Scheim, Ayden; Jain, Sonia; Sun, Xiaoying; Milloy, M. J; DeBeck, Kora; Hayashi, Kanna; Garfein, Richard S; Werb, Dan Dec 4, 2018

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BRIEF REPORT Open AccessGender differences in the provision ofinjection initiation assistance: a comparisonof three North American settingsStephanie A. Meyers1,2, Ayden Scheim2, Sonia Jain2, Xiaoying Sun2, M. J. Milloy3, Kora DeBeck3, Kanna Hayashi3,Richard S. Garfein2 and Dan Werb2,4*AbstractAim: Individuals experience differential risks in their initiation into drug injecting based on their gender. Datasuggest women are more likely to be injected after their initiator and to share injection equipment. Little is known,however, regarding how gender influences the risk that people who inject drugs (PWID) may assist others intoinjection initiation. We therefore sought to investigate the role of “initiator” gender in the provision of injectioninitiation assistance across multiple settings.Methods: We employed data from PReventing Injecting by Modifying Existing Responses (PRIMER), a multi-cohort studyinvestigating factors influencing injection initiation assistance provision. Data were drawn from three cohort studies ofPWID in San Diego, USA (STAHR II); Tijuana, Mexico (El Cuete IV); and Vancouver, Canada (VDUS). Site-specific logisticregression models were fit, with lifetime provision of injection initiation assistance as the outcome and gender as theindependent variable.Results: Overall, 3.2% (24/746) of the women and 4.6% (63/1367) of the men reported providing injection initiationassistance. In Tijuana, men were more than twice as likely to have provided injection initiation assistance after controllingfor potential confounders (adjusted odds ratio = 2.17, 95% confidence interval: 1.22–3.84). Gender was not significantlyassociated with providing injection initiation assistance in other sites.Conclusion: We identified that being male in Tijuana, specifically, was associated with providing injection initiationassistance, which could inform targeted outreach aimed at reducing the influence of PWID populations on non-injectorsin this site. This will likely require that existing interventions address gender- and site-specific factors for effectiveness.Keywords: Injection initiation, People who inject drugs, Gender, San Diego, Tijuana, VancouverBackgroundPeople who inject drugs (PWID) are disproportionatelyimpacted by blood-borne diseases such as HIV and hepa-titis C [1]. Drug injecting is also a key risk factor for over-dose, particularly with the emergence of high-potencyopioids such as fentanyl [2]. Relatedly, recently initiatedPWID have been shown to be at particularly high risk ofblood-borne disease transmission [3, 4]. This is likely dueto a reliance among inexperienced PWID on more estab-lished PWID to perform injections, which leads to aconcomitant increase in the risk of sharing used injectingequipment [3].Past literature highlights the importance of gender ininjection initiation processes and related risks [4–8].Women are particularly vulnerable to the risk ofblood-borne disease transmission during injection initi-ation events, as they are more likely to be initiated by amale intimate partner, share drug preparation equipment,and be injected after their initiator [5, 6].Though past research has established these gender dif-ferences in the initiation process of PWID [4–8], a morefulsome understanding of the gendered processes by* Correspondence: dwerb@ucsd.edu2Division of Infectious Diseases and Global Public Health, Department ofMedicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA92093-0507, USA4Li Ka Shing Knowledge Institute, St. Michael’s Hospital, 30 Bond Street,Toronto, ON M5B 1T8, CanadaFull list of author information is available at the end of the article© The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0International License (, which permits unrestricted use, distribution, andreproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link tothe Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver( applies to the data made available in this article, unless otherwise stated.Meyers et al. Harm Reduction Journal           (2018) 15:59 individuals are initiated into drug injecting is cru-cial to preventing transitions into this mode of drugconsumption and its corresponding harms. This study,therefore, sought to determine how gender may influ-ence the risk that PWID provide injection initiation as-sistance to those who have never injected, across distinctgeographic and cultural settings (i.e., San Diego, USA;Tijuana, Mexico; and Vancouver, Canada).MethodsData collectionPReventing Injecting by Modifying Existing Responses(PRIMER) investigates structural factors and interven-tions that may be effective in reducing the risk thatPWID initiate others into injection. The PRIMER studymethodology and rationale have been previouslydescribed in full [9]. In brief, PRIMER includes quantita-tive data pooled beginning in August 2014 from existingprospective community-recruited cohort studies ofPWID: the Proyecto El Cuete IV (ECIV) cohort (Tijuana,Mexico); the Study of Tuberculosis, AIDS, and HepatitisC Risk (STAHR II) cohort (San Diego, USA); the linkedVancouver Injection Drug Users Study (VDUS); and theAIDS Care Cohort to evaluate Exposure to SurvivalServices (ACCESS; Vancouver, Canada). All cohortsrelied on convenience sampling to recruit people whouse drugs, though sampling for PRIMER began at differ-ent times across sites. Additionally, VDUS and ACCESSrecruited participants aged 14 years and older, whereasSTAHR II and ECIV recruited those aged 18 and older.For the present study, eligibility was restricted to indi-viduals who reported injection drug use within the 30days prior to baseline and participants provided consentprior to enrollment. All cohort surveys collected data onsociodemographic factors and those related to drug use,including involvement in injection initiation assistanceprovision. All study sites received ethical approval fromtheir local institutional review boards (IRBs) [9], andPRIMER was approved by the University of California,San Diego, IRB.Statistical analysesCross-sectional analyses were performed at the PRIMERbaseline, defined as the visit when injection drug use initi-ation questions were first introduced to each cohort. Wedefined the outcome as ever having provided injection ini-tiation assistance (yes vs. no). The primary independentvariable was participant gender (i.e., males vs. females;only 5 participants [< 0.1%] self-identified as transgender,and we were unable to independently assess this group).In line with previous studies, and due to shared vulner-abilities between the two groups, transgender participantswere considered within the female group [10]. We alsoassessed the following covariates across all three sites: age,years since first injection, housing status, and marital sta-tus. Data on self-reported lifetime non-injection and injec-tion use of methamphetamine, cocaine, and heroin wereavailable for participants in San Diego and Tijuana andwere included as potential covariates for analyses specificto these sites. All analyses were undertaken separately bystudy site (i.e., San Diego, Tijuana, and Vancouver). Miss-ing cases comprised less than 5% of the sample (n = 35)and were excluded from the analyses [11].As determined a priori, variables associated with everproviding injection initiation assistance in bivariate ana-lysis at the p < 0.05 level were retained for inclusion in themultivariable model; participant age and years since firstinjection were also included regardless of bivariate signifi-cance. We then employed a multivariable logistic regres-sion modeling approach for each cohort in which allvariables of interest were entered simultaneously. Eachfinal multivariable model included the primary variable ofinterest (gender), age, years since first injection, and anynon-injection or injection drug use variables that retainedsignificance. All analyses were conducted using SAS OnDemand for Academics (SAS Institute Inc., Cary, NorthCarolina, USA).ResultsParticipant baseline characteristics are presented inTable 1. Table 2 presents site-specific bivariate and multi-variable results. Of the 746 women sampled, 24 (3.2%)reported providing injection initiation assistance. For the1367 men recruited, 63 (4.6%) reported providing injec-tion initiation assistance. In Tijuana, being a man wasassociated with ever having provided injection initiationassistance (adjusted odds ratio [AOR] = 2.17, 95% confi-dence interval [CI]: 1.22, 3.84, p = 0.01). In both Vancou-ver and San Diego, gender was not significantly associatedwith provision of injection initiation assistance. InVancouver, injection initiation assistance was associatedwith years since first injection (AOR = 1.04, 95% CI: 1.02,1.06, p < 0.01) and inversely associated with age (AOR =0.95, 95% CI: 0.93, 0.97, p < 0.01). In San Diego, injectioninitiation assistance provision was inversely associatedwith age (AOR = 0.95, 95% CI: 0.92, 0.98, p < 0.01). Noneof the non-injection or injection drug use variables weresignificantly associated with providing injection initiationassistance in the multivariable models.DiscussionEver providing injection initiation assistance was associ-ated with being male in Tijuana, but not in San Diego orVancouver. Age was inversely associated with this behav-ior in both San Diego and Vancouver, and a higher num-ber of years since first injection was associated with thisbehavior in Vancouver. These findings illuminate the dif-fering role of gender in injection initiation across sitesMeyers et al. Harm Reduction Journal           (2018) 15:59 Page 2 of 5and have implications for efforts to prevent injectiondrug use and related harms.Previous research has highlighted the impact of genderon injection-related risks and has reported on gender-spe-cific pathways to injection initiation [4–8]. Findings fromthe current study suggest that gender may, to some extent,determine the risk that PWID provide injection initiationassistance. Further, this appears to be highlycontext-specific and likely related to the particular socialnorms and policy practices that shape local injecting prac-tices. In Tijuana, arbitrary policing practices encouragesecrecy on behalf of PWID and foster an environmentwhere individuals are more likely to inject alone to avoidharassment by law enforcement [12]. This may accountfor the lower prevalence of injection initiation assistancewe observed in Tijuana. Women in Tijuana are morelikely to inject in their homes and with trusted individuals[13], which may make them less likely to inject in thepresence of injection-naïve individuals, or at venues inwhich initiation commonly occurs (i.e., shooting galleries)[14]. These gender-specific patterns are likely lessentrenched in San Diego and Vancouver, potentially as aTable 1 Injection initiation assistance provision and related factors among people who inject drugs in San Diego, USA; Tijuana,Mexico; and Vancouver, Canada (n = 2113)Categorical variables San Diego (N = 347)n (%)Tijuana (N = 532)n (%)Vancouver (N = 1234)n (%)Helped someone initiate injection (lifetime)Yes 130 (37.5) 76 (14.3) 288 (23.3)No 217 (62.5) 456 (85.7) 946 (76.7)GenderMen 249 (71.8) 327 (61.5) 791 (64.1)Women 98 (28.2) 205 (38.5) 443 (35.9)Housing statusStable housing 179 (51.6) 330 (62.0) 389 (31.5)Other 168 (48.4) 202 (38.0) 845 (68.5)Marital statusMarried 41 (11.8) 245 (46.1) 171 (13.9)Other 306 (88.2) 287 (54.0) 1063 (86.1)Non-injected heroin (lifetime)Yes 263 (75.9) 289 (54.3) –No 84 (24.2) 243 (45.7) –Non-injected cocaine (lifetime)Yes 317 (91.4) 361 (67.9) –No 30 (8.7) 171 (32.1) –Non-injected methamphetamine (lifetime)Yes 328 (94.5) 468 (88.0) –No 19 (5.48) 64 (12.03) –Injected heroin (lifetime)Yes 298 (85.9) 531 (99.8) –No 49 (14.1) 1 (0.2) –Injected cocaine (lifetime)Yes 259 (74.6) 321 (60.3) –No 88 (25.4) 211 (39.7) –Injected methamphetamine (lifetime)Yes 309 (89.05) 471 (88.53) –No 38 (10.95) 61 (11.47) –Age (mean years) 46.84 (SD 11.28) 41.05 (SD 8.68) 45.76 (SD 11.62)Years since first injection (mean years) 23.91 (SD 13.12) 19.90 (SD 9.46) 23.98 (SD 12.86)Note: SD standard deviationMeyers et al. Harm Reduction Journal           (2018) 15:59 Page 3 of 5result of less intense risks for physical danger arising fromlaw enforcement practices or street violence [15]. Futurequalitative research is needed to fully investigate thishypothesis.We also note the contrasting risk for injection initiationassistance associated with age and years injecting amongparticipants in Vancouver. This implies that younger par-ticipants who began injecting early were more likely tohave provided injection initiation assistance comparedwith older individuals who have been injecting for thesame number of years. Efforts to disrupt the process ofinjection initiation may be most effective in Vancouver iffocused on younger individuals with more experienceinjecting drugs.LimitationsThis study has limitations typical of observationalcross-sectional research. Non-probability sampling wasused for participant recruitment, and we cannot assumegeneralizability for populations of PWID in each studysetting [11]. Secondly, we relied on self-report, andunderreporting of experiences of initiating others intoinjecting is likely given that it is highly stigmatized [16].Additionally, it is possible that providing injection initi-ation assistance is differentially under-reported both bygender and across sites due to existing gender normsand stigma across the sites investigated.ImplicationsTo our knowledge, this is the first study investigatingthe role of gender in assisting others to initiate injectingacross multiple countries. The present study indicatesthat the likelihood of initiating others into injection druguse is impacted by one’s gender in Tijuana, one’s age inSan Diego and Vancouver, and the number of years sincefirst injection in Vancouver. These findings can providefoundations for efforts to prevent injection initiationacross sites as well as among specific high-risk subpopu-lations. We note that these findings have implicationsfor interventions seeking to prevent PWID facilitatingthe entry of others into injecting. Specifically, pathwaysto initiating others appear to be highly gendered and dis-tinct across local contexts. As such, preventing the tran-sition of individuals into injection drug use will likelyrequire that existing interventions (such as Change theCycle [17]) adapt to address site- and population-specificgender dynamics to ensure effectiveness. Future injec-tion prevention efforts should focus on providing gen-der- and context-specific prevention programs, likeone-to-one social learning programs [17, 18], targetingmen who inject drugs in Tijuana and young PWID inSan Diego and Vancouver.AbbreviationsACCESS: AIDS Care Cohort to evaluate Exposure to Survival Services study;ECIV: Proyecto El Cuete IV study; HCV: Hepatitis C virus; HIV: Humanimmunodeficiency virus; PRIMER: PReventing Injecting by Modifying ExistingTable 2 Bivariate and multivariable associations with injection initiation assistance among people who inject drugs in San Diego,USA; Tijuana, Mexico; and Vancouver, CanadaSan Diego (n = 347) Tijuana (n = 532) Vancouver (n = 1234)Unadjusted OR(95% CI)Adjusted OR(95% CI)Unadjusted OR(95% CI)Adjusted OR(95% CI)Unadjusted OR(95% CI)Adjusted OR(95% CI)Age 0.97 (0.95–0.99)** 0.95 (0.92–0.98)** 1.00 (0.97–1.02) 0.97 (0.92–1.01) 0.98 (0.97–0.99)** 0.95 (0.93–0.97)***Years since first injection 0.99 (0.97–1.01) 1.03 (0.99–1.06) 1.01 (0.99–1.04) 1.03 (0.98–1.07) 1.00 (0.99–1.01) 1.04 (1.02–1.06)***Gender(ref = women)1.18 (0.73–1.92) 1.29 (0.78–2.14) 2.07 (1.19–3.59)** 2.17 (1.22–3.84)* 0.99 (0.75–1.30) 1.10 (0.83–1.46)Marital status (ref = other) 0.75 (0.37–1.51) – 0.78 (0.48–1.28) – 1.43 (1.00–2.05) –Housing status (ref = other) 0.67 (0.43–1.04) – 1.06 (0.64–1.75) – 1.21 (0.92–1.60) –Non-injected heroin use(ref = no)1.03 (0.62–1.72) – 1.63 (0.99–2.71) – – –Non-injected cocaine use(ref = no)1.72 (0.74–3.99) – 1.63 (0.93–2.86) – – –Non-injected methamphetamineuse (ref = no)1.72 (0.61–4.90) – 1.19 (0.54–2.61) – – –Injected heroin use (ref = no) 1.04 (0.55–1.94) – – – – –Injected cocaine use (ref = no) 1.07 (0.65–1.76) – 1.31 (0.79–2.19) – – –Injected methamphetamineuse (ref = no)2.07 (0.95–4.53) – 3.55 (1.08–11.62)* 3.17 (0.96–10.52) – –Note: OR odds ratio, CI confidence interval* p < .05, ** p < .01, ***p < .001Meyers et al. Harm Reduction Journal           (2018) 15:59 Page 4 of 5Responses study; PWID: People who inject drugs; STAHR II: StudyingTuberculosis AIDS and Hepatitis C Risk study; VDUS: Vancouver InjectionDrug Users StudyAcknowledgementsWe thank all study participants from the El Cuete IV, STAHR II, and VDUS cohortsfor their willingness to participate, and thank all study staff for their support.FundingPRIMER and Dan Werb are supported by a US National Institute on DrugAbuse Avenir Award (DP2- DA040256-01), the Canadian Institutes of HealthResearch via a New Investigator Award, and the Ontario Ministry of Research,Innovation and Science via an Early Researcher Award. El Cuete IV was supportedthrough NIDA grant R37 DA019829. STAHR II was supported through NIDA grantR01DA031074. VDUS is supported by NIDA grant U01DA038886, and the ACCESSStudy is supported by NIDA grant U01DA021525. Kanna Hayashi is supportedby a Canadian Institutes of Health Research New Investigator Award(MSH-141971), a Michael Smith Foundation for Health Research ScholarAward, and the St. Paul’s Hospital Foundation. Ayden Scheim is supported by aCanadian Institutes of Health Research Fellowship and the Pierre Elliott TrudeauFoundation.Availability of data and materialsThe datasets used and/or analyzed during the current study are availablefrom the corresponding author on reasonable request.Authors’ contributionsSM was a major contributor to the conception, analysis, interpretation, andwriting for this manuscript. AS was a significant contributor to the writing ofthis manuscript. SJ and XS were responsible for the data acquisition andpreparation for the manuscript and aided in statistical interpretation. MM,KD, and KH were leaders in the collection of the data obtained from theVancouver cohort studies: VDUS and ACCESS. RG was the principal investigatorfor the STAHR II cohort study. DW is the principal investigator of the PRIMERstudy and was a significant contributor to the conceptualization, datainterpretation, and writing of this manuscript. All authors read and approvedthe final manuscript.Ethics approval and consent to participateAll participants provided consent prior to enrollment, and all study sitesreceived ethical approval from their local institutional review boards (IRBs) [9].PRIMER was approved as previously described by the University of California,San Diego Human Research Protection Program, the University of BritishColumbia-Providence Health Care Research Ethics Board, and UniversidadXochicalco School of Medicine IRB.Consent for publicationNot applicable.Competing interestsThe authors declare that they have no competing interests.Publisher’s NoteSpringer Nature remains neutral with regard to jurisdictional claims inpublished maps and institutional affiliations.Author details1School of Social Work, College of Health and Human Services, San DiegoState University, 5500 Campanile Drive, San Diego, CA 92182, USA. 2Divisionof Infectious Diseases and Global Public Health, Department of Medicine,University of California San Diego, 9500 Gilman Drive, La Jolla, CA92093-0507, USA. 3British Columbia Centre for Excellence in HIV/AIDS,608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada. 4Li Ka ShingKnowledge Institute, St. Michael’s Hospital, 30 Bond Street, Toronto, ON M5B1T8, Canada.Received: 2 August 2018 Accepted: 15 November 2018References1. World Health Organization (WHO). People who inject drugs [Internet]; 2017.p. 1. Available from: Centers for Disease Control and Prevention (CDC). Prescription drugoverdoses — a U.S. epidemic. MMWR Morb Mortal Wkly Rep. 2012;61(1):14–9 Available from: Garfein RS, Doherty MC, Monterroso ER, Thomas DL, Nelson KE, Vlahov D.Prevalence and incidence of hepatitis C virus infection among young adultinjection drug users. J Acquir Immune Defic Syndr. 18:1998 Available from: Goldsamt LA, Harocopos A, Kobrak P, Jost JJ, Clatts MC. Circumstances,pedagogy and rationales for injection initiation among new drug injectors.J Community Health. 2011;35(3):258–67.5. Frajzyngier V, Neaigus A, Gyarmathy VA, Miller M, Friedman SR. Genderdifferences in injection risk behaviors at the first injection episode. DrugAlcohol Depend. 2007;89(2–3):145–52.6. Simmons J, Rajan S, McMahon JM. Retrospective accounts of injectioninitiation in intimate partnerships. Int J Drug Policy. 2012;23(4):303–11Available from: Wright NMJ, Tompkins CNE, Sheard L. Is peer injecting a form of intimatepartner abuse? A qualitative study of the experiences of women drug users.Heal Soc Care Community. 2007;15(5):417–25.8. Doherty MC, Garfein RS, Monterroso E, Latkin C, Vlahov D. Gender differencesin the initiation of injection drug use among young adults. J Urban Health.2000;77(3):396–414 Available from: Werb D, Garfein R, Kerr T, Davidson P, Roux P, Jauffret-Roustide M, et al. Asocio-structural approach to preventing injection drug use initiation:rationale for the PRIMER study. Harm Reduct J. 2016;13(1):25 Available from: Shannon K, Kerr T, Strathdee SA, Shoveller J, Montaner JS, Tyndall MW.Prevalence and structural correlates of gender based violence among aprospective cohort of female sex workers. Bmj. 2009;339(aug11 3):b2939Available from: Tabachnik BG, Fidell LS. Using multivariate statistics. 6th ed. Northridge,California: Pearson; 2013.12. Wood EF, Werb D, Beletsky L, Rangel G, Cuevas Mota J, Garfein RS, et al.Differential experiences of Mexican policing by people who inject drugsresiding in Tijuana and San Diego. Int J Drug Policy. 2017;41:132–9 Availablefrom: file:// Firestone Cruz M, Mantsios A, Ramos R, Case P, Brouwer KC, Ramos ME, etal. A qualitative exploration of gender in the context of injection drug usein two US-Mexico border cities. AIDS Behav. 2007;11:253–62.14. Bluthenthal RN, Wenger L, Chu D, Lorvick J, Thing JP, Kral AH, et al. Factorsassociated with being asked to initiate someone into injection drug use.Drug Alcohol Depend. 2015;149:252–8.15. Beletsky L, Davis CS, Anderson E, Burris S. The law (and politics) of safeinjection facilities in the United States. Am J Public Health. 2008;98(2):231–7.16. Guise A, Horniak D, Melo J, McNeil R, Werb D. The experience of initiatinginjection drug use and its social context: a qualitative systematic review andthematic synthesis. Addiction. 2017;112(12):2098–111.17. Werb D, Buxton J, Shoveller J, Richardson C, Rowell G, Wood E.Interventions to prevent the initiation of injection drug use: a systematicreview. Drug Alcohol Depend. 2013;133(2):669–76 Available from: Small W, Wood E, Tobin D, Rikley J, Lapushinsky D, Kerr T. The injectionsupport team: a peer-driven program to address unsafe injecting in aCanadian setting. Subst Use Misuse. 2012;47(5):491–501.Meyers et al. Harm Reduction Journal           (2018) 15:59 Page 5 of 5


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