Sample Of Injection Drug Users Research Articles

A qualitative analysis of peer recruitment pressures in respondent driven sampling: Are risks above the ethical limit?

BackgroundThis paper examines peer recruitment dynamics through respondent driven sampling (RDS) with a sample of injection drug users in Hartford, CT to understand the strategies participants use to recruit peers into a study and the extent to which these strategies may introduce risks above the ethical limit despite safeguards in RDS. MethodsOut of 526 injection drug users who participated in a mixed-method RDS methodology evaluation study, a nested sample of 61 participants completed an in-depth semi-structured interview at a 2-month follow-up to explore their experiences with the recruitment process. ResultsFindings revealed that participants used a variety of strategies to recruit peers, ranging from one-time interactions to more persistent strategies to encourage participation (e.g., selecting peers that can easily be found and contacted later, following up with peers to remind them of their appointment, accompanying peers to the study site, etc.). Some participants described the more persistent strategies as helpful, while some others experienced these strategies as minor peer pressure, creating a feeling of obligation to participate. Narratives revealed that overall, the probability of experiencing study-related risks remains relatively low for most participants; however, a disconcerting finding was that higher study-related risks (e.g., relationship conflict, loss of relationship, physical fights, violence) were seen for recruits who participated but switched coupons or for recruits who decided not to participate in the study and did not return the coupon to the recruiter. ConclusionsFindings indicate that peer recruitment practices in RDS generally pose minimal risk, but that peer recruitment may occasionally exceed the ethical limit, and that enhanced safeguards for studies using peer recruitment methods are recommended. Suggestions for possible enhancements are described.

High rates of abscesses and chronic wounds in community-recruited injection drug users and associated risk factors.

Abscesses and chronic wounds are common among injection drug users (IDUs) though chronic wounds have been understudied. We assessed the risk factors associated with both acute and chronic wounds within a community-based population of IDUs frequenting the Baltimore City Needle Exchange Program (BNEP). We performed a cross-sectional study of BNEP clients aged 18 years or more who completed an in-person survey regarding active or prior wounds including abscesses (duration <8 weeks) and chronic wounds (duration ≥8 weeks), injection practices, and skin care. Factors associated with wounds were analyzed using univariate and multivariate logistic regressions. Of the 152 participants, 63.2% were men, 49.3% were white, 44.7% were African American, 34.9% had any type of current wound, 17.8% had an active abscess, and 19.7% had a current chronic wound. Abscesses were more common in women (odds ratio [OR], 2.56; 95% confidence interval [CI], 1.10-5.97) and those reporting skin-popping (OR, 5.38; 95% CI, 1.85-15.67). In a multivariate model, risk factors for an abscess included injecting with a family member/partner (adjusted OR [AOR], 4.06; 95% CI, 0.99-16.58). In a multivariable analysis of current chronic wounds, cleaning skin with alcohol before injection was protective (AOR, 0.061; 95% CI, 0.0064-0.58). Abscesses and chronic wounds were prevalent among a sample of IDUs in Baltimore. Abscesses were associated with injection practices, and chronic wounds seemed linked to varying skin and tool cleaning practices. There is a pressing need for wound-related education and treatment efforts among IDUs who are at greatest risk for skin-related morbidity.

The identification of subtypes among injection drug users: HIV and hepatitis C differences as indicated with the theory of planned behaviour

Recent studies have reported differences in terms of high-risk drug using and sexual behaviour between younger and older injection drug users (IDUs), however, no studies have looked at the clustering pattern across IDUs using the theory of planned behaviour (TPB). The TPB is useful in the prediction of behavioural outcomes. This analysis examines the interplay of TPB components and needle sharing among a sample of IDUs from Montreal, Canada. The study includes 109 eligible IDUs, recruited via respondent driven sampling. Hierarchical cluster analysis was used to identify a typology of the respondents based on the responses to TPB measure. The results indicate that, among all of the measures, descriptive and injunctive norms, HIV/hepatitis C (HCV) status, and a measure of direct control were significantly different across the subtypes. Furthermore, it was possible to identify patterns in TPB measures across the subgroups. Specifically, the two TPB measures increased from the entrenched (Cluster 1), to the chronics (Cluster 4), to the initiators (Cluster 3), with the highest reported average within the survivor group (Cluster 2). Correspondingly, the proportion of the group reporting HIV/HCV status decreased in the opposite direction. Consequently drug use and HIV/HCV treatment and prevention programs need to concentrate intervention differently for each of these heterogeneous drug user populations.

Psychometric properties of the World Health Organization quality of life assessment – brief in methadone patients: a validation study in northern Taiwan

BackgroundQuality of life (QOL) is an important outcome measure in the treatment of heroin addiction. The Taiwan version of the World Health Organization Quality of Life assessment (WHOQOL-BREF [TW]) has been developed and studied in various groups, but not specifically in a population of injection drug users. The aim of this study was to analyze the psychometric properties of the WHOQOL-BREF (TW) in a sample of injection drug users undergoing methadone maintenance treatment.MethodsA total of 553 participants were interviewed and completed the instrument. Item-response distributions, internal consistency, corrected item-domain correlation, criterion-related validity, and construct validity through confirmatory factor analysis were evaluated.ResultsThe frequency distribution of the 4 domains of the WHOQOL-BREF (TW) showed no floor or ceiling effects. The instrument demonstrated adequate internal consistency (Cronbach’s alpha coefficients were higher than 0.7 across the 4 domains) and all items had acceptable correlation with the corresponding domain scores (r = 0.32-0.73). Correlations (p < 0.01) of the 4 domains with the 2 benchmark items assessing overall QOL and general health were supportive of criterion-related validity. Confirmatory factor analysis yielded marginal goodness-of-fit between the 4-domain model and the sample data.ConclusionsThe hypothesized WHOQOL-BREF measurement model was appropriate for the injection drug users after some adjustments. Despite different patterns found in the confirmatory factor analysis, the findings overall suggest that the WHOQOL-BREF (TW) is a reliable and valid measure of QOL among injection drug users and can be utilized in future treatment outcome studies. The factor structure provided by the study also helps to understand the QOL characteristics of the injection drug users in Taiwan. However, more research is needed to examine its test-retest reliability and sensitivity to changes due to treatment.

Gender differences in circumstances surrounding first injection experience of rural injection drug users in the United States

BackgroundResearch has demonstrated that there can be substantial gender differences in circumstances surrounding initiation of injection drug use; however, little is known about the gendered dynamics of first injection in rural areas where syringe exchange is inaccessible or among those who predominantly inject prescription medications. The present study examines gender differences in first injection experience among rural residents who predominantly inject prescription opioids. MethodsInterview-administered questionnaires collected data from a sample of injection drug users (n=394) recruited from Appalachian Kentucky using respondent-driven sampling. ResultsWomen were more likely to have initiated injection due to social-pressure (p=0.001), received the drugs as a gift (p=0.011), initiated in their partner's home (p=0.004) and in their partner's presence (p<0.001), been injected by their partner (p<0.001), used an unclean syringe (p=0.026), and received the syringe from their partner (p<0.001). Women were also more likely to report having engaged in sexual intercourse before or after initiation (p<0.001). Men were more likely to have personally purchased the drugs (p=0.002), to have acquired the syringe from a pharmacy/clinic (p=0.004), and to have injected with a friend (p=0.001) or family member (p=0.020). Men were also more likely to have a friend administer the first injection (p=0.007). ConclusionsIn this population of rural drug users, notable gender differences in injection initiation were observed. Social pressure played a more substantial role in women's first injection experience, and male partners had an integral role in women's initiation.

Drug and sexual HIV risk behaviours related to knowledge of HIV serostatus among injection drug users in Houston, Texas

This study examines the association between drug and sexual HIV risk behaviours and knowledge of HIV serostatus among a sample of injection drug users, recruited into the 2009 National HIV Behavioral Surveillance project. We calculated prevalence ratios and associated 95% confidence intervals of reporting a given risk behaviour comparing injection drug users unaware of their serostatus and HIV-negative to HIV-positive injection drug users. Of 523 participants, 21% were unaware of their HIV serostatus. The three groups were not different from each other in terms of drug-use behaviours; however, injection drug users unaware of their HIV serostatus were 33% more likely to report having more than three sexual partners in the past 12 months and 45% more likely to report having unprotected sex compared to HIV-positive injection drug users. We observed markedly higher prevalence of sexual risk behaviours among injection drug users unaware of their serostatus, but drug-use risk behaviours were similar across the groups.

Frequent food insecurity among injection drug users: correlates and concerns

BackgroundFood insecurity and nutrition are two topics that are under-researched among injection drug users (IDUs). Our study examined the extent and correlates of food insecurity among a sample of IDUs and explored whether there is an association between food insecurity and injection-related HIV risk.MethodsA cross-sectional survey was conducted using interviewer-administered questionnaires. Data were collected at a needle exchange program in London, Ontario, Canada between September 2006 and January 2007. Participants included 144 English-speaking IDUs who had injected drugs in the past 30 days. Participants were asked about their socio-demographic characteristics, HIV risk behaviours, food insecurity, and health/social service use.ResultsIn the past 6 months, 54.5% of participants reported that on a daily/weekly basis they did not have enough to eat because of a lack of money, while 22.1% reported this type of food insecurity on a monthly basis. Moreover, 60.4% and 24.3% reported that they did not eat the quality or quantity of food they wanted on a daily/weekly or a monthly basis, respectively. Participants reported re-using someone else’s injection equipment: 21% re-used a needle, 19% re-used water, and 37.3% re-used a cooker. The odds of sharing injection equipment were increased for food insecure individuals.ConclusionsFindings show that IDUs have frequent and variable experiences of food insecurity and these experiences are strongly correlated with sharing of injection-related equipment. Such behaviours may increase the likelihood of HIV and HCV transmission in this population. Addressing food-related needs among IDUs is urgently needed.

Smoking, HIV Status, and HIV Risk Behaviors in a Respondent-Driven Sample of Injection Drug Users in Baltimore, Maryland: The BeSure Study

Tobacco use is the largest preventable cause of death in the United States. Associations between cigarette smoking and HIV risk behaviors were examined among 669 injection drug users (IDU) in the 2006 wave of the National HIV Behavioral Surveillance System in Baltimore, Maryland, using respondent-driven sampling. The adjusted prevalence of smoking among IDU was 92.1%, with 32.7% smoking < 1 pack of cigarettes per day (light smoking) and 59.3% smoking ≥ 1 packs per day (heavy smoking). Self-reported HIV prevalence decreased as smoking frequency increased (p = 0.001). In multivariate analysis, heavy smokers were more likely to report painkiller use and binge drinking and less likely to report anal sex or health care use in the past year than light smokers. Results suggest that health care use mediates the relationship between heavy smoking and self-reported HIV. Integrating smoking cessation with HIV prevention services could address unmet health needs in IDU.

HIV testing and willingness to get HIV testing at a peer-run drop-in centre for people who inject drugs in Bangkok, Thailand

BackgroundRegular HIV testing among people who inject drugs is an essential component of HIV prevention and treatment efforts. We explored HIV testing behaviour among a community-recruited sample of injection drug users (IDU) in Bangkok, Thailand.MethodsData collected through the Mitsampan Community Research Project were used to examine correlates of HIV testing behaviour among IDU and to explore reasons for not being tested. Multivariate logistic regression was used to examine factors associated with willingness to access HIV testing at the drug-user-run Mitsampan Harm Reduction Centre (MSHRC).ResultsAmong the 244 IDU who participated in this study, 186 (76.2%) reported receiving HIV testing in the previous six months. Enrolment in voluntary drug treatment (odds ratio [OR] = 2.34; 95% confidence interval [CI]: 1.18 - 4.63) and the tenofovir trial (OR = 44.81; 95%CI: 13.44 - 149.45) were positively associated with having been tested, whereas MSHRC use (OR = 1.78; 95%CI: 0.96 - 3.29) was marginally associated with having been tested. 56.9% of those who had not been tested reported in engaging in HIV risk behaviour in the past six months. 181 (74.2%) participants were willing to be tested at the MSHRC if testing were offered there. In multivariate analyses, willingness to get HIV testing at the MSHRC was positively associated with ever having been to the MSHRC (adjusted odds ratio [AOR] = 2.42; 95%CI: 1.21 - 4.85) and, among females, being enrolled in voluntary drug treatment services (AOR = 9.38; 95%CI: 1.14 - 76.98).ConclusionsMore than three-quarters of IDU received HIV testing in the previous six months. However, HIV risk behaviour was common among those who had not been tested. Additionally, 74.2% of participants were willing to receive HIV testing at the MSHRC. These findings provide evidence for ongoing HIV prevention education, as well potential benefits of incorporating HIV testing for IDU within peer-led harm reduction programs.

Factors associated with methadone treatment among injection drug users in Bangkok, Thailand

Little is known about the characteristics of injection drug users (IDU) who take methadone treatment in Thailand. We examined prevalence and correlates of methadone treatment among a community-recruited sample of IDU in Bangkok, Thailand. Among 273 participants, 143 (52.4%) reported accessing methadone treatment within the previous 6 months. Older age (adjusted odds ratio [AOR] = 1.90, 95% confidence interval [CI] = 1.10–3.30) and more than weekly midazolam injection (AOR = 1.85, 95% CI = 1.04–3.29) were positively associated, whereas alcohol use (AOR = 0.34, 95% CI = 0.18–0.63) and noninjection methamphetamine use (AOR = 0.49, 95% CI = 0.29–0.85) were negatively associated with methadone treatment. In subanalyses, 98.6% of IDU on methadone continued to inject drugs, and the most common reason for stopping methadone was becoming incarcerated (49%). Evidence-based addiction treatment in the form of methadone maintenance therapy, with attention paid to concomitant midazolam injection in this setting, should be implemented.

Compulsory drug detention center experiences among a community-based sample of injection drug users in Bangkok, Thailand

BackgroundDespite Thailand's official reclassification of drug users as "patients" deserving care and not "criminals," the Thai government has continued to rely heavily on punitive responses to drug use such as "boot camp"-style compulsory "treatment" centers. There is very little research on experiences with compulsory treatment centers among people who use drugs. The work reported here is a first step toward filling that gap.MethodsWe examined experiences of compulsory drug treatment among 252 Thai people who inject drugs (IDU) participating in the Mitsampan Community Research Project in Bangkok. Multivariate logistic regression was used to identify factors independently associated with a history of compulsory treatment experience.ResultsIn total, 80 (31.7%) participants reported a history of compulsory treatment. In multivariate analyses, compulsory drug detention experience was positively associated with current spending on drugs per day (adjusted odds ratio [AOR] = 1.86; 95%CI: 1.07 - 3.22) and reporting drug planting by police (AOR = 1.81; 95%CI: 1.04 - 3.15). Among those with compulsory treatment experience, 77 (96.3%) reported injecting in the past week, and no difference in intensity of drug use was observed between those with and without a history of compulsory detention.ConclusionThese findings raise concerns about the current approach to compulsory drug detention in Thailand. Exposure to compulsory drug detention was associated with police abuse and high rates of relapse into drug use, although additional research is needed to determine the precise impact of exposure to this form of detention on future drug use. More broadly, compulsory "treatment" based on a penal approach is not consistent with scientific evidence on addressing drug addiction and should be phased out in favor of evidence-based interventions.

Commentary on Genberg et al. (2011): The structural vulnerability imposed by hypersegregated US inner-city neighborhoods - a theoretical and practical challenge for substance abuse research

Commentary on Genberg et al. (2011): The structural vulnerability imposed by hypersegregated US inner-city neighborhoods - a theoretical and practical challenge for substance abuse research

Age at First Alcoholic Drink as Predictor of Current HIV Sexual Risk Behaviors Among a Sample of Injection Drug Users (IDUs) and Non-IDUs who are Sexual Partners of IDUs, in St. Petersburg, Russia

This study investigates whether age at first alcoholic drink is associated with sexual risk behaviors among injection drug users (IDUs) and non-IDUs who are sexual partners of IDUs in St. Petersburg, Russia. A path analysis was used to test a model of age at first drink, age at sexual debut, age at first drug use, current substance use patterns and current sexual risk behaviors among 558 participants. Results revealed that age at first drink had an effect on multiple sex partners through age at sexual debut and injection drug use, but no effect on unprotected sex. Age at first drug use was not related to sexual risk behaviors. Investigation of age of drinking onset may provide useful information for programs to reduce sexual risk behaviors and injection drug use. Different paths leading to unprotected sex and multiple sexual partners call for different approaches to reduce sexual risk behaviors among this population.

Accessing a diverse sample of injection drug users in San Francisco through respondent-driven sampling

AimsInjection drug users (IDU) are the second most affected population by HIV in San Francisco and the United Stated after men who have sex with men (MSM). Behavioral surveillance data that include the diversity of the population at risk are necessary to develop effective programs for IDU. DesignWe conducted a cross-sectional behavioral survey of IDU using respondent-driven sampling (RDS) in San Francisco. The present analysis focuses the performance of the sampling method in reaching the diversity of the population as a pre-requisite for representative data. ParticipantsOver 32weeks, 571 eligible IDU were recruited, of whom 477 (83.5%) with complete records were included in analysis. FindingsThe age range was 18–70years, with 36% age 50years or older. The majority (56%) were homeless. Male, MSM, African-Americans and Non-Hispanic Whites comprised 71%, 28%, 36% and 35% of IDU, respectively. Twenty-two percent had “ever shared needles in the past 12months,” and 57% reported that they had “shared drugs” in the past 12months. Peer referral chains were able to cross-recruit IDU by diverse demographic characteristics, drug use related behaviors, program access and use, and other factors relevant to reaching and conducting prevention research on this population. ConclusionRDS appears to be an effective sampling tool that reaches diverse populations of IDU, including many who may be missed by drug treatment and HIV prevention services in San Francisco and potentially in other urban areas.

Methamphetamine injection and syringe sharing among a community-recruited sample of injection drug users in Bangkok, Thailand

The recent growth in methamphetamine use internationally has raised concerns about the relationship between methamphetamine use and HIV infection. However, the risks associated with methamphetamine injection have not been fully described, particularly outside of Western countries. Therefore, we sought to examine the relationship between methamphetamine injection and syringe sharing among injection drug users (IDU) in Bangkok, Thailand. Using bivariate statistics and multivariate logistic regression, we examined the prevalence of methamphetamine injection and the relationship between more than weekly methamphetamine injection and syringe sharing among a community-recruited sample of IDU participating in the Mitsampan Community Research Project in Bangkok. During June and July 2009, 311 IDU participated in this study, including 91 (29.3%) women. In total, 114 (36.7%) participants reported having injected methamphetamine ("yaba") twice or more per week in the past six months. In multivariate analyses, after adjustment for potential social, demographic and behavioral confounders, syringe sharing remained independently associated with injecting methamphetamine more than once per week (adjusted odds ratio=2.86, 95% confidence interval: 1.59-5.15). Over one-third of a community-recruited sample of Thai IDU reported more than weekly injection of methamphetamine, and methamphetamine injection was independently associated with syringe sharing. Essential HIV prevention services targeting IDU, such as syringe exchange and evidence-based addiction treatment, should be included in interventional efforts to address methamphetamine use in Thailand.

Addiction Treatment and Stable Housing among a Cohort of Injection Drug Users

BackgroundUnstable housing and homelessness is prevalent among injection drug users (IDU). We sought to examine whether accessing addiction treatment was associated with attaining stable housing in a prospective cohort of IDU in Vancouver, Canada.MethodsWe used data collected via the Vancouver Injection Drug User Study (VIDUS) between December 2005 and April 2010. Attaining stable housing was defined as two consecutive “stable housing” designations (i.e., living in an apartment or house) during the follow-up period. We assessed exposure to addiction treatment in the interview prior to the attainment of stable housing among participants who were homeless or living in single room occupancy (SRO) hotels at baseline. Bivariate and multivariate associations between the baseline and time-updated characteristics and attaining stable housing were examined using Cox proportional hazard regression models.Principal FindingsOf the 992 IDU eligible for this analysis, 495 (49.9%) reported being homeless, 497 (50.1%) resided in SRO hotels, and 380 (38.3%) were enrolled in addiction treatment at the baseline interview. Only 211 (21.3%) attained stable housing during the follow-up period and of this group, 69 (32.7%) had addiction treatment exposure prior to achieving stable housing. Addiction treatment was inversely associated with attaining stable housing in a multivariate model (adjusted hazard ratio [AHR] = 0.71; 95% CI: 0.52–0.96). Being in a partnered relationship was positively associated with the primary outcome (AHR = 1.39; 95% CI: 1.02–1.88). Receipt of income assistance (AHR = 0.65; 95% CI: 0.44–0.96), daily crack use (AHR = 0.69; 95% CI: 0.51–0.93) and daily heroin use (AHR = 0.63; 95% CI: 0.43–0.92) were negatively associated with attaining stable housing.ConclusionsExposure to addiction treatment in our study was negatively associated with attaining stable housing and may have represented a marker of instability among this sample of IDU. Efforts to stably house this vulnerable group may be occurring in contexts outside of addiction treatment.

Overdose experiences among injection drug users in Bangkok, Thailand

BackgroundAlthough previous studies have identified high levels of drug-related harm in Thailand, little is known about illicit drug overdose experiences among Thai drug users. We sought to investigate non-fatal overdose experiences and responses to overdose among a community-recruited sample of injection drug users (IDU) in Bangkok, Thailand.MethodsData for these analyses came from IDU participating in the Mit Sampan Community Research Project. The primary outcome of interest was a self-reported history of non-fatal overdose. We calculated the prevalence of past overdose and estimated its relationship with individual, drug-using, social, and structural factors using multivariate logistic regression. We also assessed the prevalence of ever witnessing an overdose and patterns of response to overdose.ResultsThese analyses included 252 individuals; their median age was 36.5 years (IQR: 29.0 - 44.0) and 66 (26.2%) were female. A history of non-fatal overdose was reported by 75 (29.8%) participants. In a multivariate model, reporting a history of overdose was independently associated with a history of incarceration (Adjusted Odds Ratio [AOR] = 3.83, 95% Confidence Interval [CI]: 1.52 - 9.65, p = 0.004) and reporting use of drugs in combination (AOR = 2.48, 95% CI: 1.16 - 5.33, p = 0.019). A majority (67.9%) reported a history of witnessing an overdose; most reported responding to the most recent overdose using first aid (79.5%).ConclusionsExperiencing and witnessing an overdose were common in this sample of Thai IDU. These findings support the need for increased provision of evidence-based responses to overdose including peer-based overdose interventions.

Recent Incarceration Linked to Cutaneous Injection-Related Infections Among Active Injection Drug Users in a Canadian Setting

Cutaneous injection-related infections (CIRI), such as abscesses and cellulitis, are the cause of a substantial burden of morbidity and mortality among injection drug users (IDU). The possible contribution of exposure to correctional environments to CIRI risk has not been fully investigated. Thus, we sought to test the possible relationship between incarceration and CIRI using data from a community-based sample of IDU. Data for these analyses was from the Scientific Evaluation of Supervised Injecting (SEOSI) cohort, linked with administrative records of a local ED in Vancouver, Canada. Using longitudinal analysis we assessed the relationship between the number of ED visits for CIRI care and recent incarceration in a multivariate model including information on possible confounders. Between June 2004 and December 2006, 901 individuals were eligible for our analysis. Of these, 214 (9.6%) visited the ED for CIRI care at least once during the study period. The incidence of ED care for CIRI was 72.9 per 100 person years. In a multivariate model, recent incarceration was associated with a greater number of ED visits for CIRI care (adjusted relative rate = 1.56, 95% confidence interval: 1.31-1.85, P < 0.001). The need for ED treatment for CIRI was common among a sample of local IDU. Exposure to correctional environments was an independent risk factor for visiting the ED for CIRI care, suggesting improvements in infection control in local prisons is urgently needed.

Social-Level Correlates of Shooting Gallery Attendance: A Focus on Networks and Norms

The purpose of this study was to examine the association between social network characteristics and peer norms related to sharing needles and shooting gallery use. Multivariate logistic regression modeling was used to identify factors that were independently associated with shooting gallery use among a sample of injection drug users recruited in Baltimore, Maryland. Of 842 study participants, 35% reported attending a shooting gallery in the past 6months. Social networks of shooting gallery users were larger, had a greater number of injectors and crack smokers, were younger and less dense with fewer kin members compared to networks of non-gallery attenders. A greater proportion of those who used a gallery perceived that their peers shared needles and that peers would not disapprove if they used a dirty needle. Future research is needed to understand how social networks and peer norms are specific to behavioral settings and how this may impede adoption of preventive behaviors.

Neighborhood Poverty and Injection Cessation in a Sample of Injection Drug Users

Neighborhood socioeconomic environment may be a determinant of injection drug use cessation. The authors used data from a prospective cohort study of Baltimore City, Maryland, injection drug users assessed between 1990 and 2006. The study examined the relation between living in a poorer neighborhood and the probability of injection cessation among active injectors, independent of individual characteristics and while respecting the temporality of potential confounders, exposure, and outcome. Participants' residences were geocoded, and the crude, adjusted, and inverse probability of exposure weighted associations between neighborhood poverty and injection drug use cessation were estimated. Weighted models showed a strong association between neighborhood poverty and injection drug use cessation; living in a neighborhood with fewer than 10%, compared with more than 30%, of residents in poverty was associated with a 44% increased odds of not injecting in the prior 6 months (odds ratio = 1.44, 95% confidence interval: 1.14, 1.82). Results show that neighborhood environment may be an important determinant of drug injection behavior independent of individual-level characteristics.