Evaluating the impact of Mexico's drug policy reforms on people who inject drugs in Tijuana, B.C., Mexico, and San Diego, CA, United States: a binational mixed methods research agenda

Potential benefits of using ecological momentary assessment to study high-risk polydrug use

BACKGROUND

While studies have documented both the feasibility and acceptability of using ecological momentary assessment (EMA) to study drug use, there is little empirical research assessing participants' perceptions of utilizing this technology-driven approach.

METHODS

Participants were English-speaking persons ≥18 years old who reported injection drug use and sequential (e.g., alcohol followed by opioid use) or simultaneous (i.e., injecting heroin and cocaine in one shot) polydrug use within 30 days recruited in San Diego, CA and Philadelphia, PA. Participants (N=36) completed two cell phone-based EMA simulations assessing mood, drug use, HIV risk behaviors, and daily activities, followed by semi-structured interviews that probed for potential benefits of participation over time. Qualitative analysis involved an iterative process of reviewing texts from the interviews to create a coding framework, which was then applied to all transcripts to identify themes.

RESULTS

Findings suggest participants may derive indirect benefits from participation in EMA studies including: improved self-worth from helping others; experiencing increased social support through utilization of the study-provided mobile device for non-research purposes; and most importantly, increased self-reflection, which could lead to therapeutic and intervention-like effects such as decreased substance use or reduced HIV risk.

CONCLUSIONS

Participants identified a variety of potential benefits from participating in a study that utilizes EMA. This research suggests that benefits are highly salient for individuals involved in studies of polydrug use.

Perceived Treatment Need and Latent Transitions in Heroin and Methamphetamine Polydrug Use among People who Inject Drugs in Tijuana, Mexico

People who inject drugs (PWID) in Tijuana, Mexico, use heroin and/or methamphetamine. While polydrug use is associated with HIV risk behavior, less is known about the stability of polydrug use patterns over time and how polydrug use is related to perceived treatment need. Within a cohort of PWID in Tijuana (N = 735) we sought to (1) characterize subgroups of polydrug and polyroute use from baseline to six months; (2) determine the probabilities of transitioning between subgroups; and (3) examine whether self-reported need for help for drug use modified these transition probabilities. Latent transition analysis (LTA) identified four latent statuses: heroin-only injection (38% at both baseline and follow-up); co-injection of heroin with methamphetamine (3% baseline, 15% follow-up); injection of heroin and methamphetamine (37% baseline, 32% follow-up); and polydrug and polyroute users who injected heroin and both smoked and injected methamphetamine (22% baseline, 14% follow-up). Heroin-only injectors had the highest probability of remaining in the same latent status at follow-up. The majority reported great or urgent need for treatment (51%) and these PWID had greater odds of transitioning to a higher-risk status at follow-up, emphasizing the need for evidence-based drug treatment options for PWID.

Prevalence and Correlates of Heroin-Methamphetamine Co-Injection Among Persons Who Inject Drugs in San Diego, California, and Tijuana, Baja California, Mexico

OBJECTIVE

Although persons who inject drugs (PWID) in the western United States-Mexico border region are known to inject both heroin and methamphetamine, little is known about the prevalence and risks associated with co-injection of this depressant-stimulant combination (also known as "goofball" and "Mexican speedball").

METHOD

Baseline data from parallel cohort studies of PWID conducted concurrently in San Diego, CA, and Tijuana, Mexico, were used to estimate the prevalence and identify correlates of heroin-methamphetamine co-injection. PWID older than 18 years of age who reported injecting illicit drugs in the past month (N = 1,311; 32.7% female) were recruited in San Diego (n = 576) and Tijuana (n = 735) and completed interviewer-administered questionnaires. Bivariate and multivariable logistic regression analyses were used to identify correlates of heroin-meth-amphetamine co-injection.

RESULTS

The prevalence of co-injection in the past 6 months was 39.9% overall and was higher in Tijuana (55.8%) than in San Diego (19.8%). In multivariable analyses adjusting for study cohort, distributive syringe sharing, purchasing syringes prefilled with drugs, finding it hard to get new syringes, reporting great or urgent need for treatment, and younger age were independently associated with co-injection. Past-6-month overdose was significantly associated with higher odds of co-injection in San Diego than in Tijuana.

CONCLUSIONS

These findings indicate that heroin-methamphetamine co-injection is more common in Tijuana than in San Diego, yet this practice was only associated with overdose in San Diego. Heroin-methamphetamine coinjection was also independently associated with HIV-associated injection risk behaviors. Overdose-prevention interventions should address co-injection of depressants and stimulants.

Cross-border injection drug use and HIV and hepatitis C virus seropositivity among people who inject drugs in San Diego, California

BACKGROUND

The prevalence of HIV and Hepatitis C Virus (HCV) are significantly lower among people who inject drugs (PWID) in San Diego, CA, USA compared with PWID in Tijuana, Mexico, located directly across the border. We investigated associations between cross-border injection drug use (IDU), HIV and HCV seroprevalence and engagement in injecting risk behaviours while on each side of the border.

METHODS

Using baseline interviews and serologic testing data from STAHR II, a longitudinal cohort study of PWID in San Diego, bivariate and multivariable logistic regression analyses examined associations between recent (past six months) cross-border IDU and HIV and HCV antibody seropositivity, socio-demographics, drug use characteristics, and participants' connections to, and perceptions about Mexico. Chi-squared tests and McNemar tests examined associations between cross-border IDU and injecting risk behaviours.

RESULTS

Of the 567 participants (93% U.S.-born, 73% male, median age 45 years), 86 (15%) reported recent cross-border IDU. Cross-border IDU was not associated with HIV (OR: 0.85, 95% CI: 0.37-1.95) or HCV seropositivity (OR: 1.01, 95% CI: 0.62-1.65). Age, identifying as Hispanic or Latino/a, and being concerned about risk of violence when travelling to Mexico were independently associated with decreased odds of recent cross-border IDU. Injecting cocaine at least weekly, having ever lived in Mexico and knowing PWID who reside in Mexico were associated with increased odds of recent cross-border IDU. PWID who reported cross-border IDU were significantly less likely to engage in receptive needle sharing, equipment sharing, and public injection while in Mexico compared with in San Diego (all p<0.001).

CONCLUSION

Prevalence of HIV and HCV infection was similar among PWID who had and had not injected in Mexico, possibly due to practising safer injecting while in Mexico. Research is needed to elucidate contextual factors enabling U.S. PWID to inject safely while in Mexico.

Potential Risks of Ecological Momentary Assessment Among Persons Who Inject Drugs

BACKGROUND

Ecological momentary assessment (EMA)-which often involves brief surveys delivered via mobile technology-has transformed our understanding of the individual and contextual micro-processes associated with legal and illicit drug use. However, little empirical research has focused on participant's perspective on the probability and magnitude of potential risks in EMA studies.

OBJECTIVES

To garner participant perspectives on potential risks common to EMA studies of illicit drug use.

METHODS

We interviewed 38 persons who inject drugs living in San Diego (CA) and Philadelphia (PA), United States. They completed simulations of an EMA tool and then underwent a semi-structured interview that systematically explored domains of risk considered within the proposed revisions to the Federal Policy for the Protection of Human Subjects or the "Common Rule." Interviews were transcribed verbatim and coded systematically to explore psychological, physical, social, legal, and informational risks from participation.

RESULTS

Participants perceived most risks to be minimal. Some indicated that repetitive questioning about mood or drug use could cause psychological (i.e., anxiety) or behavioral risks (i.e., drug use relapse). Ironically, the questions that were viewed as risky were considered motivational to engage in healthy behaviors. The most cited risks were legal and social risks stemming from participant concerns about data collection and security.

IMPORTANCE

Improving our understanding of these issues is an essential first step to protect human participants in future EMA research. We provide a brief set of recommendations that can aid in the design and ethics review of the future EMA protocol with substance using populations.

Health-damaging policing practices among persons who inject drugs in Mexico: Are deported migrants at greater risk?

BACKGROUND

Evidence-based public health and criminal justice policies aimed at addressing the structurally vulnerable population of persons who inject drugs (PWID) and who are involved in the immigrant enforcement and deportation system are lacking. Policing practices are critical structural determinants of HIV among PWID. PWID in Mexico who have been deported from the US are at elevated risk of HIV.

METHODS

From 2011 to 2013, 733 PWID were recruited to complete structured questionnaires, including past 6-month experiences with police. Eligible PWID were 18 years or older, had injected in the past month, and resided in Tijuana, Mexico with no intentions of moving. To determine if deportation status was associated with experiences of arrests and problematic policing practices, we conducted separate multivariate logistic regression models for independent policing variables.

RESULTS

In multivariate analyses, deportation status was independently associated with higher odds of being arrested (Adjusted Odds Ratio (AOR): 1.45; 95% Confidence Interval (CI): 1.02-2.05), being asked for a bribe (AOR: 1.39; 95% CI: 1.05-2.04), and being forced to leave a place of residence (AOR: 2.00; 95% CI: 1.08-3.70) in the past 6 months.

CONCLUSION

Results highlight a previously poorly understood elements of the US-deportation experience: migrants' experiences with law enforcement post-deportation and the role of deportation policies and practices as structural drivers of public health risk in destination countries. We provide policy recommendations for Mexico and the US based on our findings, which have potential application in other countries seeking to improve enforcement and related policing practices from a public health perspective.

Hope Amidst Horror: Documenting the Effects of the "War On Drugs" Among Female Sex Workers and Their Intimate Partners in Tijuana, Mexico

Sensationalistic media coverage has fueled stereotypes of the Mexican border city of Tijuana as a violent battleground of the global drug war. While the drug war shapes health and social harms in profoundly public ways, less visible are the experiences and practices of hope that forge communities of care and represent more private responses to this crisis. In this article, we draw on ethnographic fieldwork and photo elicitation with female sex workers who inject drugs and their intimate, non-commercial partners in Tijuana to examine the personal effects of the drug war. Drawing on a critical phenomenology framework, which links political economy with phenomenological concern for subjective experience, we explore the ways in which couples try to find hope amidst the horrors of the drug war. Critical visual scholarship may provide a powerful alternative to dominant media depictions of violence, and ultimately clarify why this drug war must end.

Addiction-Related Stigma and Discrimination: A Qualitative Study in Treatment Centers in Mexico City

Social rejection of drug use is greater than that directed at other psychiatric conditions, like depression and anxiety, which may lead to social exclusion of substance users and prevent them from seeking and receiving treatment.

OBJECTIVE

The objective of this study is to investigate the stigma and discrimination related to addiction in treatment centers in Mexico City.

METHODS

Data are from a broad mixed methods study. The present study is a qualitative analysis of 35 in-depth interviews of drug users, family members, and providers, using guidelines for the exploration of experiences of stigma and discrimination related to substance abuse. A thematic analysis was carried out using specialized software (Atlas.ti 6.2.23).

RESULTS

The common practices of stigma and discrimination (e.g., judging, mockery, inappropriate comments, overprotection, and hostile looks), were identified in participant testimonies. The narratives provide evidence of varied conditions of social and gender inequality, as well as experience of violence and abuse, that refer to a structural context of discrimination surrounding addiction, and that constitute obstacles to treatment.

CONCLUSIONS

The findings allow for a description of the stigmatization process surrounding addiction as a shared problem that requires the implementation of coordinated treatment strategies. They also suggest the need for more comprehensive policies of inclusion, based on human rights, which favor prevention and treatment.

Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico

INTRODUCTION AND AIMS

Patterns of polydrug use among people who inject drugs (PWID) may be differentially associated with overdose and unique human immunodeficiency virus (HIV) risk factors. Subgroups of PWID in Tijuana, Mexico, were identified based on substances used, route of administration, frequency of use and co-injection indicators.

DESIGN AND METHODS

Participants were PWID residing in Tijuana age ≥18 years sampled from 2011 to 2012 who reported injecting an illicit substance in the past month (n = 735). Latent class analysis identified discrete classes of polydrug use characterised by 11 indicators of past 6 months substance use. Multinomial logistic regression examined class membership association with HIV risk behaviours, overdose and other covariates using an automated three-step procedure in mplus to account for classification error.

RESULTS

Participants were classified into five subgroups. Two polydrug and polyroute classes were defined by use of multiple substances through several routes of administration and were primarily distinguished from each other by cocaine use (class 1: 5%) or no cocaine use (class 2: 29%). The other classes consisted primarily of injectors: cocaine, methamphetamine and heroin injection (class 3: 4%); methamphetamine and heroin injection (class 4: 10%); and heroin injection (class 5: 52%). Compared with the heroin-only injection class, memberships in the two polydrug and polyroute use classes were independently associated with both HIV injection and sexual risk behaviours.

DISCUSSION AND CONCLUSIONS

Substance use patterns among PWID in Tijuana are highly heterogeneous, and polydrug and polyroute users are a high-risk subgroup who may require more tailored prevention and treatment interventions. [Meacham MC, Roesch SC, Strathdee SA, Lindsay S, Gonzalez-Zuniga P, Gaines TL. Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico. Drug Alcohol Rev 2018;37:128-136].

The Spatial-Temporal Pattern of Policing Following a Drug Policy Reform: Triangulating Self-Reported Arrests With Official Crime Statistics

BACKGROUND

In 2009, Mexico enacted a drug policy reform (Narcomenudeo) designed to divert persons possessing small amounts of illicit drugs to treatment rather than incarceration. To assess reform impact, this study examines the spatial-temporal trends of drug-related policing in Tijuana, Mexico post-enactment.

METHOD

Location of self-reported arrests (N = 1,160) among a prospective, community-recruited cohort of people who inject drugs (PWID) in Tijuana (N = 552) was mapped across city neighborhoods. Official police reports detailing drug-related arrests was triangulated with PWID self-reported arrests. Exploratory spatial data analysis examined the distribution of arrests and spatial association between both datasets across three successive years, 2011-2013.

RESULTS

In 2011, over half of PWID reported being detained but not officially charged with a criminal offense; in 2013, 90% of arrests led to criminal charges. Official drug-related arrests increased by 67.8% (p <.01) from 2011 to 2013 despite overall arrest rates remaining stable throughout Tijuana. For each successive year, we identified a high degree of spatial association between the location of self-reported and official arrests (p <.05).

CONCLUSION

Two independent data sources suggest that intensity of drug law enforcement had risen in Tijuana despite the promulgation of a public health-oriented drug policy reform. The highest concentrations of arrests were in areas traditionally characterized by higher rates of drug crime. High correlation between self-reported and official arrest data underscores opportunities for future research on the role of policing as a structural determinant of public health.

Differential experiences of Mexican policing by people who inject drugs residing in Tijuana and San Diego

BACKGROUND

Research among people who inject drugs (PWIDs) in the USA and Mexico has identified a range of adverse health impacts associated with policing of PWIDs. We employed a mixed methods design to investigate how PWIDs from San Diego and Mexico experienced policing in Tijuana, and how these interactions affect PWIDs behavior, stratifying by country of origin.

METHODS

In 2012-2014, 575 PWIDs in San Diego, 102 of whom had used drugs in Mexico in the past six months, were enrolled in the STAHR-II study, with qualitative interviews conducted with a subsample of 20 who had recently injected drugs in Mexico. During this period, 735 PWIDs in Tijuana were also enrolled in the El Cuete-IV study, with qualitative interviews conducted with a subsample of 20 recently stopped by police. We calculated descriptive statistics for quantitative variables and conducted thematic analysis of qualitative transcripts. Integration of these data involved comparing frequencies across cohorts and using qualitative themes to explain and explore findings.

RESULTS

Sixty-one percent of San Diego-based participants had been recently stopped by law enforcement officers (LEOs) in Mexico; 53% reported it was somewhat or very likely that they would be arrested while in Mexico because they look like a drug user. Ninety percent of Tijuana-based participants had been recently stopped by LEOs; 84% reported it was somewhat or very likely they could get arrested because they look like a drug user. Participants in both cohorts described bribery and targeting by LEOs in Mexico. However, most San Diego-based participants described compliance with bribery as a safeguard against arrest and detention, with mistreatment being rare. Tijuana-based participants described being routinely targeted by LEOs, were frequently detained, and reported instances of sexual and physical violence. Tijuana-based participants described modifying how, where, and with whom they injected drugs in response; and experienced feelings of stress, anxiety, and powerlessness. This was less common among San Diego-based participants, who mostly attempted to avoid contact with LEOs in Mexico while engaging in risky injection behavior.

CONCLUSION

Experiences of discrimination and stigma were reported by a larger proportion of PWIDs living in Mexico, suggesting that they may be subject to greater health harms related to policing practices compared with those residing in the USA. Our findings reinforce the importance of efforts to curb abuse and align policing practices with public health goals in both the US and Mexico.

A socio-structural approach to preventing injection drug use initiation: rationale for the PRIMER study

BACKGROUND

Injection drug use remains a primary driver of HIV and HCV-related harms globally. However, there is a gap in efforts to prevent individuals from transitioning into injecting. People who inject drugs (PWID) play a key role in the transition of others into injecting, and while behavioral interventions have been developed to address this phenomenon, socio-structural approaches remain unexplored. To that end, we hypothesize that certain interventions designed to reduce injecting-related risk behaviors may also reduce the risk that PWID expose and introduce others into injecting. Identifying the preventive potential of existing interventions will inform broader efforts to prevent injecting and related harms.

METHODS

The Preventing Injecting by Modifying Existing Responses (PRIMER) study is a multi-country mixed methods study with an aim to investigate whether specific interventions (e.g., opioid substitution therapy, supervised injection facilities, stable housing, incarceration environments) and related factors (e.g., public injecting and gender) influence the likelihood that PWID initiate others into injecting. This study will (1) investigate the PWID participation in injection initiation; (2) identify factors influencing the risk that PWID expose others to or facilitate injection initiation; (3) describe drug scene roles that increase the risk of PWID facilitating injection initiation; and (4) evaluate the impact of structural, social, or biomedical interventions on the risk that PWID facilitate injection initiation. It does so by pooling observational data from cohort studies of PWID in six cities: Vancouver, Canada; San Diego, USA; Tijuana, Mexico; Paris, Marseille, and Bordeaux, France.

RESULTS

Team members are conducting a prospective, multi-site study of PWID (n = 3050) in North America and France that includes quantitative and qualitative data collection through four separate cohort studies of PWID (San Diego, STAHR II; Tijuana, El Cuete IV; Vancouver, V-DUS; Bordeaux, Marseille, Paris and Strasbourg, COSINUS).

CONCLUSIONS

PRIMER is the largest study of injection initiation to date and the first to investigate structural approaches to preventing injection drug use initiation. Findings have the potential to inform the development and scale up of new and existing interventions to prevent transitions into injecting.

TRIAL REGISTRATION

Preventing Injecting by Modifying Existing Responses (PRIMER), NIDA DP2-DA040256-01 .

Connecting the dots: network data and models in HIV epidemiology

Effective HIV prevention requires knowledge of the structure and dynamics of the social networks across which infections are transmitted. These networks most commonly comprise chains of sexual relationships, but in some populations, sharing of contaminated needles is also an important, or even the main mechanism that connects people in the network. Whereas network data have long been collected during survey interviews, new data sources have become increasingly common in recent years, because of advances in molecular biology and the use of partner notification services in HIV prevention and treatment programmes. We review current and emerging methods for collecting HIV-related network data, as well as modelling frameworks commonly used to infer network parameters and map potential HIV transmission pathways within the network. We discuss the relative strengths and weaknesses of existing methods and models, and we propose a research agenda for advancing network analysis in HIV epidemiology. We make the case for a combination approach that integrates multiple data sources into a coherent statistical framework.

Spatial patterns of arrests, police assault and addiction treatment center locations in Tijuana, Mexico

AIMS

In the context of a public health-oriented drug policy reform in Mexico, we assessed the spatial distribution of police encounters among people who inject drugs (PWID) in Tijuana, determined the association between these encounters and the location of addiction treatment centers and explored the association between police encounters and treatment access.

DESIGN

Geographically weighted regression (GWR) and logistic regression analysis using prospective spatial data from a community-recruited cohort of PWID in Tijuana and official geographical arrest data from the Tijuana Municipal Police Department.

SETTING

Tijuana, Mexico.

PARTICIPANTS

A total of 608 participants (median age 37; 28.4% female) in the prospective Proyecto El Cuete cohort study recruited between January and December 2011.

MEASUREMENTS

We compared the mean distance of police encounters and a randomly distributed set of events to treatment centers. GWR was undertaken to model the spatial relationship between police interactions and treatment centers. Logistic regression analysis was used to investigate factors associated with reporting police interactions.

FINDINGS

During the study period, 27.5% of police encounters occurred within 500 m of treatment centers. The GWR model suggested spatial correlation between encounters and treatment centers (global R(2)  = 0.53). Reporting a need for addiction treatment was associated with reporting arrest and police assault [adjusted odds ratio = 2.74, 95% confidence interval (CI) = 1.25-6.02, P = 0.012].

CONCLUSIONS

A geospatial analysis suggests that, in Mexico, people who inject drugs are at greater risk of being a victim of police violence if they consider themselves in need of addiction treatment, and their interactions with police appear to be more frequent around treatment centers.

Engagement in the HIV Care Continuum among Key Populations in Tijuana, Mexico

In Tijuana, Mexico, HIV is concentrated in sub-epidemics of key populations: persons who inject drugs (PWID), sex workers (SW), and men who have sex with men (MSM). To date, data on engagement in the HIV care continuum among these key populations, particularly in resource-constrained settings, are sparse. We pooled available epidemiological data from six studies (N = 3368) to examine HIV testing and treatment uptake in these key populations; finding an overall HIV prevalence of 5.7 %. Of the 191 identified HIV-positive persons, only 11.5 % knew their HIV-positive status and 3.7 % were on ART. Observed differences between these HIV-positive key populations suggest PWID (vs. non-PWID) were least likely to have previously tested or initiate HIV care. MSM (vs. non-MSM) were more likely to have previously tested but not more likely to know their HIV-positive status. Of persons aware of their HIV-positive status, SW (vs. non-SW) were more likely to initiate HIV care. Findings suggest engagement of key populations in HIV treatment is far below estimates observed for similarly resource-constrained generalized epidemics in sub-Saharan Africa. These data provide one of the first empirical-snapshots highlighting the extent of HIV treatment disparities in key populations.

Police Victimization Among Persons Who Inject Drugs Along the U.S.-Mexico Border

OBJECTIVE

Problematic policing practices are an important driver of HIV infection among persons who inject drugs (PWID) in the U.S.-Mexico border region. This study identifies factors associated with recent (i.e., past 6 months) police victimization (e.g., extortion, physical and sexual violence) in the border city of Tijuana, Mexico.

METHOD

From 2011 to 2013, 733 PWID (62% male) were recruited in Tijuana and completed a structured questionnaire. Eligible participants were age 18 years or older, injected illicit drugs within the past month, and spoke Spanish or English. Multivariable logistic regression analyses identified correlates of recent experiences of police victimization (e.g., bribes, unlawful confiscation, physical and sexual violence).

RESULTS

Overall, 56% of PWID reported a recent police victimization experience in Tijuana. In multivariable logistic regression analyses, factors independently associated with recent police victimization included recent injection of methamphetamine (adjusted odds ratio [AOR] = 1.62; 95% CI [1.18, 2.21]) and recently received injection assistance by a "hit doctor" (AOR = 1.56; 95% CI [1.03, 2.36]). Increased years lived in Tijuana (AOR = 0.98 per year; 95% CI [0.97, 0.99]) and initiating drug use at a later age (AOR = 0.96 per year; 95% CI [0.92, 0.99]) were inversely associated with recent police victimization.

CONCLUSIONS

Physical drugusing markers may increase PWID susceptibility to police targeting and contribute to experiences of victimization. Interventions aimed at reducing police victimization events in the U.S.-Mexico border region should consider PWID's drug-using behaviors. Reducing problematic policing practices may be a crucial public health strategy to reduce HIV risk among PWID in this region.

Factors associated with patterns of mobile technology use among persons who inject drugs

BACKGROUND

New and innovative methods of delivering interventions are needed to further reduce risky behaviors and increase overall health among persons who inject drugs (PWID). Mobile health (mHealth) interventions have potential for reaching PWID; however, little is known about mobile technology use (MTU) in this population. In this study, the authors identify patterns of MTU and identified factors associated with MTU among a cohort of PWID.

METHODS

Data were collected through a longitudinal cohort study examining drug use, risk behaviors, and health status among PWID in San Diego, California. Latent class analysis (LCA) was used to define patterns of MTU (i.e., making voice calls, text messaging, and mobile Internet access). Multinomial logistic regression was then used to identify demographic characteristics, risk behaviors, and health indicators associated with mobile technology use class.

RESULTS

In LCA, a 4-class solution fit the data best. Class 1 was defined by low MTU (22%, n = 100); class 2, by PWID who accessed the Internet using a mobile device but did not use voice or text messaging (20%, n = 95); class 3, by primarily voice, text, and connected Internet use (17%, n = 91); and class 4, by high MTU (41%, n = 175). Compared with low MTU, high MTU class members were more likely to be younger, have higher socioeconomic status, sell drugs, and inject methamphetamine daily.

CONCLUSION

The majority of PWID in San Diego use mobile technology for voice, text, and/or Internet access, indicating that rapid uptake of mHealth interventions may be possible in this population. However, low ownership and use of mobile technology among older and/or homeless individuals will need to be considered when implementing mHealth interventions among PWID.

Understanding differences in HIV/HCV prevalence according to differentiated risk behaviors in a sample of PWID in rural Puerto Rico

BACKGROUND

Blood contained in needles and injection equipment has been identified as a vector for HIV and HCV transmission among people who inject drugs (PWID). Yet, there is often a wide discrepancy in prevalence for both viruses. While microbiological differences between viruses influence prevalence, other variables associated with the way drugs are acquired and used, also play a role.

METHODS

Respondent-driven sampling (RDS) methods recruited a sample of 315 current intravenous drug users in rural Puerto Rico. Information about type and frequency of use, HIV and HVC risk behaviors (sharing needles, cookers, cotton, and water), sexual behaviors, and alcohol use was collected. HIV and HCV statuses were assessed via rapid antibody tests. T tests compare means of participants who tested positive (reactive) to those who tested negative. Logistic regression analyses were used to validate the association of the risk factors involved.

RESULTS

Tests showed a significant difference in HIV (6%) and HCV (78.4%) prevalence among a population of current PWID. The main risk behaviors in HCV transmission are the sharing of injection "works", (e.g., cookers, cotton, and water). Sharing works occurred more than twice as often as the sharing of needles, and HCV+ and HCV- individuals reported the same needle sharing habits.

CONCLUSIONS

Washing and rinsing injection works with water seems to prevent HIV transmission, but it is unable to prevent HCV infection. While education about the need to clean injection equipment with bleach might be beneficial, equipment sharing--and the subsequent risk of HVC--might be unavoidable in a context where participants are forced to pool resources to acquire and use intravenous drugs.

Risk of violence in drug rehabilitation centers: perceptions of people who inject drugs in Tijuana, Mexico

Background

In 2009, Mexico reformed its health law to partially decriminalize drug possession considered for personal use and to increase mandatory referrals to certified drug rehabilitation centers in lieu of incarceration. Concurrently, news media reported violent attacks perpetrated by drug cartels against Mexican drug rehabilitation centers and instances of human rights violations by staff against people who inject drugs (PWID) in treatment. In many cases, these violent situations took place at “Peer Support” (Ayuda Mutua) drug rehabilitation centers that house a large number of drug-dependent PWID. In an effort to understand barriers to treatment uptake, we examined prevalence and correlates of perceived risk of violence at drug rehabilitation centers among PWID in Tijuana, Mexico.

Methods

Secondary analysis of baseline data collected between March 2011 and May 2013 of PWID recruited into a prospective cohort study in Tijuana. Interviewer-administered surveys measured perceived risk of violence at drug rehabilitation centers by asking participants to indicate their level of agreement with the statement “going to rehabilitation puts me at risk of violence”. Logistic regression was used to examine factors associated with perceived risk of violence.

Results

Of 733 PWID, 34.5 % perceived risk of violence at drug rehabilitation centers. In multivariate analysis, reporting ever having used crystal methamphetamine and cocaine (separately), having a great or urgent need to get help for drug use, and ever receiving professional help for drug/alcohol use were negatively associated with perceived risk of violence at drug rehabilitation centers, while having been told by law enforcement that drug rehabilitation attendance is mandatory was positively associated with perceived risk of violence. All associations were significant at a 0.05 alpha level.

Conclusion

The perception of violence at drug rehabilitation centers among PWID does not represent the lived experience of those PWID who attended professionalized services, reported a great or urgent need to get help for their drug use and had a history of using crystal and cocaine. Professionalizing service delivery and engaging law enforcement in their new role of decriminalization and service referral for PWID could address the perceptions of violence at drug rehabilitation centers. Similarly, health authorities should expand periodic inspections at drug rehabilitation centers to guarantee quality service provision and minimize PWIDs’ concerns about violence.

Electronic supplementary material

The online version of this article (doi:10.1186/s13011-015-0044-z) contains supplementary material, which is available to authorized users.

Predictors of needle exchange program utilization during its implementation and expansion in Tijuana, Mexico

OBJECTIVE

Until the early 2000s, there was only one needle exchange program (NEP) offered in Mexico. In 2004, the second Mexican NEP opened in Tijuana, but its utilization has not been studied. We studied predictors of initiating NEP during its early expansion in Tijuana, Mexico.

METHODS

From April 2006 to April 2007, people who inject drugs (PWID) residing in Tijuana who had injected within the last month were recruited using respondent-driven sampling. Weighted Poisson regression incorporating generalized estimating equations was used to identify predictors of initiating NEP, while accounting for correlation between recruiter and recruits.

RESULTS

NEP uptake increased from 20% at baseline to 59% after 6 months. Among a subsample of PWID not accessing NEP at baseline (n = 480), 83% were male and median age was 37 years (Interquartile Range: 32-43). At baseline, 4.4% were HIV-infected and 5.9% had syphilis titers >1:8. In multivariate models, factors associated with NEP initiation (p < .05) were attending shooting galleries (Adjusted Relative Risk [ARR]: 1.54); arrest for track-marks (ARR: 1.38); having a family member that ever used drugs (ARR: 1.37); and having a larger PWID network (ARR: 1.01 per 10 persons). NEP initiation was inversely associated with obtaining syringes at pharmacies (ARR: .56); earning >2500 pesos/month (ARR: .66); and reporting needle sharing (ARR: .71).

CONCLUSIONS

Uptake of NEP expansion in Tijuana was vigorous among PWID. We identified a range of factors that influenced the likelihood of NEP initiation, including police interaction. These findings have important implications for the scale-up of NEP in Mexico.

Institutional stakeholder perceptions of barriers to addiction treatment under Mexico's drug policy reform

Mexico has experienced disproportionate drug-related harms given its role as a production and transit zone for illegal drugs destined primarily for the USA. In response, in 2009, the Mexican federal government passed legislation mandating pre-arrest diversion of drug-dependent individuals towards addiction treatment. However, this federal law was not specific about how the scale-up of the addiction treatment sector was to be operationalised. We therefore conducted in-depth qualitative interviews with key 'interactors' in fields affected by the federal legislation, including participants from the law enforcement, public health, addiction treatment, and governmental administration sectors. Among 19 participants from the municipal, state and federal levels were interviewed and multiple barriers to policy reform were identified. First, there is a lack of institutional expertise to implement the reform. Second, the operationalisation of the reform was not accompanied by a coordinated action plan. Third, the law is an unfunded mandate. Institutional barriers are likely hampering the implementation of Mexico's policy reform. Addressing the concerns expressed by interactors through the scale-up of services, the provision of increased training and education programmes for stakeholders and a coordinated action plan to operationalise the policy reform are likely needed to improve the policy reform process.

Prevalence and Correlates of the Use of Prefilled Syringes Among Persons Who Inject Drugs in San Diego, CA

Persons who inject drugs (PWID) are at increased risk for blood-borne virus (BBV) infections and overdose resulting from high-risk injecting practices. Studies of prefilled syringe use ([PFSU] using a syringe that already contained drug solution when it was obtained by the user), an injection practice previously described in Eastern Europe, suggest that it increases susceptibility to BBV. However, little is known about this practice in the USA. Data were obtained from an ongoing cohort study of PWID to determine the prevalence and assess correlates of PFSU in San Diego, CA. Baseline interviews assessed socio-demographics and drug use behaviors. Logistic regression was used to identify factors independently associated with ever using a prefilled syringe (yes/no). Participants (n = 574) were predominately males (73.9%) and white (50.9%) with a mean age of 43.4 years (range 18-80); 33.3% reported ever using prefilled syringes, although only 4.9% reported use in the past 6 months. In multivariable analyses, PFSU was independently associated with ever having a rushed injection due to police presence [adjusted odds ratio (AOR) = 2.51, 95% CI 1.66, 3.79], ever being in prison (AOR = 1.80, 95% CI 1.23, 2.63), injecting most often in public versus private places in the past 6 months (AOR = 1.66, 95% CI 1.11, 2.48), and injecting drugs in Mexico (AOR = 1.70, 95% CI 1.16, 2.49). Results indicate that a history of PFSU is common and associated with environmental factors that may also increase risk for adverse health outcomes. Studies are needed to better understand PFSU in order to develop interventions to prevent adverse outcomes associated with their use.

HIV Transmission Networks in the San Diego-Tijuana Border Region

BACKGROUND

HIV sequence data can be used to reconstruct local transmission networks. Along international borders, like the San Diego-Tijuana region, understanding the dynamics of HIV transmission across reported risks, racial/ethnic groups, and geography can help direct effective prevention efforts on both sides of the border.

METHODS

We gathered sociodemographic, geographic, clinical, and viral sequence data from HIV infected individuals participating in ten studies in the San Diego-Tijuana border region. Phylogenetic and network analysis was performed to infer putative relationships between HIV sequences. Correlates of identified clusters were evaluated and spatiotemporal relationships were explored using Bayesian phylogeographic analysis.

FINDINGS

After quality filtering, 843 HIV sequences with associated demographic data and 263 background sequences from the region were analyzed, and 138 clusters were inferred (2-23 individuals). Overall, the rate of clustering did not differ by ethnicity, residence, or sex, but bisexuals were less likely to cluster than heterosexuals or men who have sex with men (p = 0.043), and individuals identifying as white (p ≤ 0.01) were more likely to cluster than other races. Clustering individuals were also 3.5 years younger than non-clustering individuals (p < 0.001). Although the sampled San Diego and Tijuana epidemics were phylogenetically compartmentalized, five clusters contained individuals residing on both sides of the border.

INTERPRETATION

This study sampled ~ 7% of HIV infected individuals in the border region, and although the sampled networks on each side of the border were largely separate, there was evidence of persistent bidirectional cross-border transmissions that linked risk groups, thus highlighting the importance of the border region as a "melting pot" of risk groups.

FUNDING

NIH, VA, and Pendleton Foundation.

A police education programme to integrate occupational safety and HIV prevention: protocol for a modified stepped-wedge study design with parallel prospective cohorts to assess behavioural outcomes

INTRODUCTION

Policing practices are key drivers of HIV among people who inject drugs (PWID). This paper describes the protocol for the first study to prospectively examine the impact of a police education programme (PEP) to align law enforcement and HIV prevention. PEPs incorporating HIV prevention (including harm reduction programmes like syringe exchange) have been successfully piloted in several countries but were limited to brief pre-post assessments; the impact of PEPs on policing behaviours and occupational safety is unknown.

OBJECTIVES

Proyecto ESCUDO (SHIELD) aims to evaluate the efficacy of the PEP on uptake of occupational safety procedures, as assessed through the incidence of needle stick injuries (NSIs) (primary outcome) and changes in knowledge of transmission, prevention and treatment of HIV and viral hepatitis; attitudes towards PWID, adverse behaviours that interfere with HIV prevention and protective behaviours (secondary outcomes).

METHODS/ANALYSIS

ESCUDO is a hybrid type I design that simultaneously tests an intervention and an implementation strategy. Using a modified stepped-wedge design involving all active duty street-level police officers in Tijuana (N = ∼ 1200), we will administer one 3 h PEP course to groups of 20-50 officers until the entire force is trained. NSI incidence and geocoded arrest data will be assessed from department-wide de-identified data. Of the consenting police officers, a subcohort (N=500) will be randomly sampled from each class to undergo pre-PEP and post-PEP surveys with a semiannual follow-up for 2 years to assess self-reported NSIs, attitudes and behaviour changes. The impact on PWIDs will be externally validated through a parallel cohort of Tijuana PWIDs.

ETHICS/DISSEMINATION

Research ethics approval was obtained from the USA and Mexico. Findings will be disseminated through open access to protocol materials through the Law Enforcement and HIV Network.

TRIAL REGISTRATION NUMBER

NCT02444403.

Association between non-fatal opioid overdose and encounters with healthcare and criminal justice systems: Identifying opportunities for intervention

BACKGROUND

Accidental overdose, driven largely by opioids, is a leading cause of death among people who inject drugs (PWIDs). We conducted secondary analysis of data from a cohort of PWIDs to identify venues where high-risk PWID could be targeted by overdose education/naloxone distribution (OEND) programs.

METHODS

573 PWIDs completed a quantitative survey between June, 2012 and January, 2014, which was analyzed using multivariable logistic regression. The dependent variable was a dichotomous indicator of experiencing a heroin/opioid-related overdose in the past six months. Independent variables included: demographics, drug use behavior, and encounters with two venues - the health care and criminal justice systems - that could serve as potential venues for OEND programs.

RESULTS

Almost half (41.5%) reported ever experiencing a heroin/opioid overdose, and 45 (7.9%) reported experiencing at least one heroin/opioid overdose in the past six months. In the final multivariable model, receiving care in a hospital in the past six months (Adjusted Odds Ratio [AdjOR] 4.08, 95% Confidence Interval [C.I.] 2.07, 8.04, p<0.001) and being arrested for drug possession in the past six months (AdjOR 5.17, 95% C.I. 2.37, 11.24, p<0.001) were associated with experiencing an opioid overdose in the past six months.

CONCLUSIONS

Identifying venues outside of those that traditionally target services to PWIDs (i.e., syringe exchange programs) will be critical to implementing OEND interventions at a scale sufficient to address the growing epidemic of heroin/opioid related deaths. Clinical settings, such as hospitals, and drug-related encounters with law enforcement officers are promising venues for the expansion of OEND programs.

Place of Residence Moderates the Relationship Between Emotional Closeness and Syringe Sharing Among Injection Drug Using Clients of Sex Workers in the US-Mexico Border Region

Injection drug-using men from the US and Mexico who purchase sex in Tijuana, Mexico are at risk for transmitting HIV to their contacts in both countries via syringe sharing. We used social network methods to understand whether place of residence (US vs. Mexico) moderated the effect of emotional closeness on syringe sharing. We interviewed 199 drug-using men who reported paying/trading for sex in Tijuana, Mexico using an epidemiological and social network survey and collected samples for HIV/STI testing. Seventy-two men reported using injection drugs with 272 network contacts. Emotional closeness was strongly associated with syringe sharing in relationship where the partner lives in the US, while the relationship between emotional closeness and syringe sharing was considerably less strong in dyads where the partner lives in Mexico. Efforts to reduce HIV risk behaviors in emotionally close relationships are needed, and could benefit from tailoring to the environmental context of the relationship.

Incidence and Predictors of HIV and Sexually Transmitted Infections Among Female Sex Workers and Their Intimate Male Partners in Northern Mexico: A Longitudinal, Multilevel Study

Preventing human immunodeficiency virus (HIV) infection and other sexually transmitted infections (STIs) requires an understanding of sexual relationship factors beyond the individual level. We estimated HIV/STI incidence and identified time-varying predictors of STI acquisition in a prospective cohort study of female sex workers and their intimate (noncommercial) male partners in northern Mexico. From 2010 to 2013, couples underwent behavioral and biological assessments biannually for 24 months. Among 413 initially HIV-uninfected participants, 8 seroconverted during follow-up. Incidence of HIV (1.12 cases/100 person-years (PY)), chlamydia (9.47 cases/100 PY), active syphilis (4.01 cases/100 PY), and gonorrhea (1.78 cases/100 PY) was higher among women than among men (HIV: P = 0.069; all STIs combined: P < 0.001). In multivariable conditional logistic regression with individual fixed effects and correlated error terms within couples, risk of STI acquisition was significantly higher among women who had recently used cocaine, crack, or methamphetamine (adjusted odds ratio (OR) = 2.13, 95% confidence interval (CI): 1.07, 4.28). STI risk was lower among women who reported physically assaulting their male partners (adjusted OR = 0.44, 95% CI: 0.22, 0.86) and among men whose female partners had regular sex-work clients (adjusted OR = 0.38, 95% CI: 0.14, 1.03). Improving vulnerable couples' sexual health will require addressing the contexts in which drug use, interpersonal conflict, and economic vulnerability converge.

Prevalence and correlates of neck injection among people who inject drugs in Tijuana, Mexico

INTRODUCTION AND AIMS

Injecting drugs in the neck has been related to adverse health conditions such as jugular vein thrombosis, deep neck infections, aneurysm, haematomas, airway obstruction, vocal cord paralysis and wound botulism, among others. We identified prevalence and correlates of neck injection among people who inject drugs (PWID) in Tijuana, Mexico.

DESIGN AND METHODS

Beginning in 2011, PWID aged ≥18 years who injected drugs within the last month were recruited into a prospective cohort. At baseline and semi-annually, PWID completed interviewer-administered surveys soliciting data on drug-injecting practices. Logistic regression was used to identify predictors of injecting in the neck as the most frequent injection site at a single visit.

RESULTS

Of 380 PWID, 35.3% injected in the neck at least once in the past 6 months, among whom 71.6% reported it as their most common injection site, the most common injecting site after the arms (47%). Controlling for age, years injecting and injecting frequency, injecting heroin and methamphetamine two or more times per day and having sought injection assistance were associated with injecting in the neck [adjusted odds ratios (AOR): 2.12; 95% confidence intervals (CI): 1.27-3.53 and AOR: 2.65; 95% CI: 1.52-4.53 respectively].

DISCUSSION AND CONCLUSIONS

Injecting in the neck was very common among PWID in Tijuana and was associated with polydrug use and seeking injection assistance. Tailoring harm reduction education interventions for individuals who provide injection assistance ('hit doctors') may allow for the dissemination of safe injecting knowledge to reduce injection-related morbidity and mortality.

Examining the spatial distribution of law enforcement encounters among people who inject drugs after implementation of Mexico's drug policy reform

In 2009, Mexico decriminalized the possession of small amounts of illicit drugs for personal use in order to refocus law enforcement resources on drug dealers and traffickers. This study examines the spatial distribution of law enforcement encounters reported by people who inject drugs (PWID) in Tijuana, Mexico to identify concentrated areas of policing activity after implementation of the new drug policy. Mapping the physical location of law enforcement encounters provided by PWID (n = 461) recruited through targeted sampling, we identified hotspots of extra-judicial encounters (e.g., physical/sexual abuse, syringe confiscation, and money extortion by law enforcement) and routine authorized encounters (e.g., being arrested or stopped but not arrested) using point density maps and the Getis-Ord Gi* statistic calculated at the neighborhood-level. Approximately half of the participants encountered law enforcement more than once in a calendar year and nearly one third of these encounters did not result in arrest but involved harassment or abuse by law enforcement. Statistically significant hotspots of law enforcement encounters were identified in a limited number of neighborhoods located in areas with known drug markets. At the local-level, law enforcement activities continue to target drug users despite a national drug policy that emphasizes drug treatment diversion rather than punitive enforcement. There is a need for law enforcement training and improved monitoring of policing tactics to better align policing with public health goals.

Police bribery and access to methadone maintenance therapy within the context of drug policy reform in Tijuana, Mexico

AIMS

In 2009, Mexico passed legislation to decriminalize drug possession and improve access to addiction treatment. We undertook research to assess the implementation of the reform among a cohort of people who inject drugs (PWID) in Tijuana. This study specifically sought to determine whether discretionary policing practices like extortion impact access to methadone maintenance therapy (MMT) in Tijuana, a city characterized by high levels of drug-related harms.

METHODS

Generalized estimating equation analyses were used to construct longitudinal confounding models to determine the association between paying a police bribe and MMT enrolment among PWID in Tijuana enrolled in a prospective cohort study. Outcome of interest was MMT enrolment in the past six months. Data on police interactions and MMT enrolment were also obtained.

RESULTS

Between October, 2011 and September, 2013, 637 participants provided 1825 observations, with 143 (7.8%) reports of MMT enrolment during the study period. In a final confounding model, recently reporting being forced to pay a bribe to police was significantly associated with an increased likelihood of accessing MMT (adjusted odds ratio=1.69, 95% confidence interval: 1.02-2.81, p=0.043). However, in 56 (39.2%) cases, MMT enrolment ceased within six months. The majority of participant responses cited the fact that MMT was too expensive (69.1%).

DISCUSSION

Levels of MMT access were low. PWID who experienced police extortion were more likely to access MMT at baseline, though this association decreased during the study period. Coupled with the costs of MMT, this may compromise MMT retention among PWID.

High dead-space syringe use among people who inject drugs in Tijuana, Mexico

BACKGROUND

High dead-space syringes (HDSS) are believed to confer an elevated risk of acquiring HIV and other blood-borne infections.

OBJECTIVES

We identified prevalence and correlates of HDSS use among injection drug users (IDU) in Tijuana, Mexico, where syringe purchase and possession is legal without a prescription.

METHODS

Beginning in 2011, IDU who reported being 18 years or older and injected drugs within the last month were recruited into a prospective study. At baseline and semi-annually, 557 IDU underwent HIV-testing and interviewer-administered surveys. Logistic regression was used to identify correlates of using HDSS.

RESULTS

Of 557 IDU, 40% had ever used HDSS, mostly because no other syringe type was available (72%), or because they were easier to get (20%). Controlling for sex and age at first injection, use of HDSS was associated with cocaine as the first drug injected (Adjusted Odds Ratio [AOR]: 2.68; Confidence Interval 95% [CI]: 1.15-6.22), having been stopped or arrested by police (AOR: 1.84; 95% CI: 1.11-3.07), being deported from the US (AOR: 1.64; 95% CI:1.06-2.53), and believing it is illegal to carry syringes (AOR:1.78; 95% CI: 1.01-3.15).

CONCLUSION

Use of HDSS is surprisingly common among IDU in Tijuana. Efforts are needed to expand coverage of low-dead space syringes through existing syringe exchange programs. Education is required to increase awareness of the harms associated with HDSS, and to inform IDU that syringe possession is legal across Mexico.

Individual and socio-environmental factors associated with unsafe injection practices among young adult injection drug users in San Diego

Unsafe injection practices significantly increase the risk of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection among injection drug users (IDUs). We examined individual and socio-environmental factors associated with unsafe injection practices in young adult IDUs in San Diego, California. Of 494 IDUs, 46.9 % reported receptive syringe sharing and 68.8 % sharing drug preparation paraphernalia in the last 3 months. Unsafe injection practices were associated with increased odds of having friends who injected drugs with used syringes, injecting with friends or sexual partners, and injecting heroin. Perceived high susceptibility to HIV and perceived barriers to obtaining sterile syringes were associated with increased odds of receptive syringe sharing, but not with sharing injection paraphernalia. Over half the IDUs reported unsafe injection practices. Our results suggest that personal relationships might influence IDUs' perceptions that dictate behavior. Integrated interventions addressing individual and socio-environmental factors are needed to promote safe injection practices in this population.

Mexico's "ley de narcomenudeo" drug policy reform and the international drug control regime

It has been over half a century since the landmark Single Convention on Narcotic Drugs was adopted, for the first time unifying international drug policy under a single treaty aimed at limiting use, manufacture, trade, possession, and trafficking of opiates, cannabis, and other narcotics. Since then, other international drug policy measures have been adopted, largely emphasizing enforcement-based approaches to reducing drug supply and use. Recently, in response to concerns that the historic focus on criminalization and enforcement has had limited effectiveness, international drug policies have begun to undergo a paradigm shift as countries seek to enact their own reforms to partially depenalize or deregulate personal drug use and possession. This includes Mexico, which in 2009 enacted national drug policy reform partially decriminalizing possession of small quantities of narcotics for personal consumption while also requiring drug treatment for repeat offenders. As countries move forward with their own reform models, critical assessment of their legal compatibility and effectiveness is necessary. In this commentary we conduct a critical assessment of the compatibility of Mexico's reform policy to the international drug policy regime and describe its role in the current evolving drug policy environment. We argue that Mexico's reform is consistent with flexibilities allowed under international drug treaty instruments and related commentaries. We also advocate that drug policy reforms and future governance efforts should be based on empirical evidence, emphasize harm reduction practices, and integrate evidence-based evaluation and implementation of drug reform measures.

Use of synthetic cathinones and cannabimimetics among injection drug users in San Diego, California

BACKGROUND

Use of synthetic cathinones (SC) and cannabimimetics (i.e., "THC homologues" [TH]) is associated with adverse health effects. We investigated the epidemiology of synthetic drug use among a cohort of injection drug users (IDUs) in San Diego, California.

METHODS

We used logistic regression analysis to identify correlates of SC and TH use among 485 IDUs enrolled from June 2012 to September 2013.

RESULTS

Seven percent of participants reported ever using SC and 30% reported ever using TH. In multivariate logistic regression, age and recent hospitalization were significantly associated with odds of SC use (Adjusted Odds Ratio [AOR] 0.93, 95% Confidence Interval [C.I.] 0.90, 0.97; and AOR 2.34 95% C.I. 1.00, 5.49, respectively) and TH use (AOR 0.96, 95% C.I. 0.94, 0.98; and AOR 2.62, 95% C.I. 1.47, 4.68, respectively). Use of methamphetamine (AOR 9.35, 95% C.I. 1.20, 72.79) and club drugs in the past six months (AOR 3.38, 95% C.I. 1.17, 9.76) were significantly associated with SC use. Being on probation/parole (AOR 2.42, 95% C.I. 1.44, 4.07), initiating injection drug use with stimulants (AOR 1.89 95% C.I. 1.13, 3.16), and past six-month marijuana (AOR 9.22, 95% C.I. 4.49, 18.96) and prescription drug use (AOR 1.98, 95% C.I. 1.20, 3.27) were significantly associated with TH use.

CONCLUSIONS

A considerable proportion of IDU use synthetic drugs and may experience harms associated with their use. Findings have implications for criminal justice system management. Prevention efforts should emphasize the risks associated with rapidly changing synthetic formulations, and the potential harms associated with polydrug use.