Contextual Predictors of Injection Drug Use Among Black Adolescents and Adults in US Metropolitan Areas, 1993-2007

Drug use practices and wound care experiences in the age of xylazine adulteration

INTRODUCTION

Exposure to xylazine has been associated with wounds distinct from typical injection-related skin and soft tissue infections. We sought to understand drug use and wound care practices, and treatment experiences of people who use drugs (PWUD) in a high-prevalence area of xylazine adulteration.

METHODS

In August 2023, we surveyed adult PWUD reporting at least one past-year drug use-related wound across three Massachusetts syringe service programs. Using a representative illustration, participants indicated if they had experienced a xylazine wound in the past 90 days. We compared demographic, drug use factors, wound care, and medical treatment experiences among those with and without xylazine wounds. We also conducted additional content analysis of open-ended responses.

RESULTS

Of the 171 respondents, 87 % (n=148) had a xylazine wound in the past 90 days. There were no statistically significant demographic differences between those with and without xylazine wounds. Among those primarily injecting (n=155), subcutaneous injection was nearly ten times more likely among people with xylazine wounds. For those with xylazine wounds (n=148), many engaged in heterogeneous wound self-treatment practices, and when seeking medical care, 74 % experienced healthcare stigma and 58 % had inadequate pain and withdrawal management.

CONCLUSION

People with self-identified xylazine wounds were more likely to engage in subcutaneous injection and faced several barriers seeking medical wound treatment. Programs serving people exposed to xylazine should work to support safer injection practices, including alternatives to injecting and improving access to high-quality, effective wound care. Further study is warranted to understand the causes, promoters, and prevention of xylazine-related wounds.

Social-spatial network structures among young urban and suburban persons who inject drugs in a large metropolitan area

BACKGROUND

Recent studies underscore the significance of adopting a syndemics approach to study opioid misuse, overdose, hepatitis C (HCV) and HIV infections, within the broader context of social and environmental contexts in already marginalized communities. Social interactions and spatial contexts are crucial structural factors that remain relatively underexplored. This study examines the intersections of social interactions and spatial contexts around injection drug use. More specifically, we investigate the experiences of different residential groups among young (aged 18-30) people who inject drugs (PWID) regarding their social interactions, travel behaviors, and locations connected to their risk behaviors. By doing so, we aim to achieve a more comprehensive understanding of the multidimensional risk environment, thereby facilitating the development of informed policies.

METHODS

We collected and examined data regarding young PWID's egocentric injection network and geographic activity spaces (i.e., where they reside, inject drugs, purchase drugs, and meet sex partners). Participants were stratified based on the location of all place(s) of residence in the past year i.e., urban, suburban, and transient (both urban and suburban) to i) elucidate geospatial concentration of risk activities within multidimensional risk environments based on kernel density estimates; and ii) examine spatialized social networks for each residential group.

RESULTS

Participants were mostly non-Hispanic white (59%); 42% were urban residents, 28% suburban, and 30% transient. We identified a spatial area with concentrated risky activities for each residential group on the West side of Chicago in Illinois where a large outdoor drug market area is located. The urban group (80%) reported a smaller concentrated area (14 census tracts) compared to the transient (93%) and suburban (91%) with 30 and 51 tracts, respectively. Compared to other areas in Chicago, the identified area had significantly higher neighborhood disadvantages. Significant differences were observed in social network structures and travel behaviors: suburban participants had the most homogenous network in terms of age and residence, transient participants had the largest network (degree) and more non-redundant connections, while the urban group had the shortest travel distance for all types of risk activities.

CONCLUSION

Distinct residential groups exhibit varying patterns of network interaction, travel behaviors, and geographical contexts related to their risk behaviors. Nonetheless, these groups share common concentrated risk activity spaces in a large outdoor urban drug market area, underscoring the significance of accounting for risk spaces and social networks in addressing syndemics within PWID populations.

Creation and Validation of a New Socio-built Environment Index Measure of Opioid Overdose Risk for Use in Both Non-urban and Urban Settings

A great deal of literature has examined features of the physical built environment as predictors of opioid overdose and other substance use-related outcomes. Other literature suggests that social characteristics of settings are important predictors of substance use outcomes. However, there is a dearth of literature simultaneously measuring both physical and social characteristics of settings in an effort to better predict opioid overdose. There is also a dearth of literature examining built environment as a predictor of overdose in non-urban settings. The present study presents a novel socio-built environment index measure of opioid overdose risk comprised of indicators measuring both social and physical characteristics of settings - and developed for use in both urban and non-urban settings - and assesses its validity among 565 urban, suburban, and rural New Jersey municipalities. We found that this novel measure had good convergent validity, based on significant positive associations with a social vulnerability index and crime rates, and significant negative associations with a municipal revitalization index and high school graduation rates. The index measure had good discriminant validity, based on lack of association with three different racial isolation indices. Finally, our index measure had good health outcome-based criterion validity, based on significant positive associations with recent overdose mortality. There were no major differences between rural, suburban, and urban municipalities in validity analysis findings. This promising new socio-built environment risk index measure could improve ability to target and allocate resources to settings with the greatest risk, in order to improve their impact on overdose outcomes.

Social-spatial network structures among young urban and suburban persons who inject drugs in a large metropolitan area

Background

It is estimated that there are 1.5% US adult population who inject drugs in 2018, with young adults aged 18-39 showing the highest prevalence. PWID are at a high risk of many blood-borne infections. Recent studies have highlight the importance of employing the syndemic approach to study opioid misuse, overdose, HCV and HIV, along with the social and environmental contexts where these interrelated epidemics occur in already marginalized communities. Social interactions and spatial contexts are important structural factors that are understudied.

Methods

Egocentric injection network and geographic activity spaces for young (aged 18-30) PWID and their injection, sexual, and social support network members (i.e., where reside, inject drugs, purchase drugs, and meet sex partners) were examined using baseline data from an ongoing longitudinal study (n=258). Participants were stratified based on the location of all place(s) of residence in the past year i.e., urban, suburban, and transient (both urban and suburban) to i) elucidate geospatial concentration of risk activities within multi-dimensional risk environments based on kernel density estimates; and ii) examine spatialized social networks for each residential group.

Results

Participants were mostly non-Hispanic white (59%); 42% were urban residents, 28% suburban, and 30% transient. We identified a spatial area with concentrated risky activities for each residence group on the West side of Chicago where a large outdoor drug market area is located. The urban group (80%) reported a smaller concentrated area (14 census tracts) compared to the transient (93%) and suburban (91%) with 30 and 51 tracts, respectively. Compared to other areas in Chicago, the identified area had significantly higher neighborhood disadvantages (e.g., higher poverty rate, p <0.001). Significant ( p <0.01 for all) differences were observed in social network structures: suburban had the most homogenous network in terms of age and residence, transient participants had the largest network (degree) and more non-redundant connections.

Conclusion

We identified concentrated risk activity spaces among PWID from urban, suburban, and transient groups in a large outdoor urban drug market area, which highlights the need for considering the role of risk spaces and social networks in addressing the syndemics in PWID populations.

Incorporating space and time into random forest models for analyzing geospatial patterns of drug-related crime incidents in a major U.S. metropolitan area

The opioid crisis has hit American cities hard, and research on spatial and temporal patterns of drug-related activities including detecting and predicting clusters of crime incidents involving particular types of drugs is useful for distinguishing hot zones where drugs are present that in turn can further provide a basis for assessing and providing related treatment services. In this study, we investigated spatiotemporal patterns of more than 52,000 reported incidents of drug-related crime at block group granularity in Chicago, IL between 2016 and 2019. We applied a space-time analysis framework and machine learning approaches to build a model using training data that identified whether certain locations and built environment and sociodemographic factors were correlated with drug-related crime incident patterns, and establish the top contributing factors that underlaid the trends. Space and time, together with multiple driving factors, were incorporated into a random forest model to analyze these changing patterns. We accommodated both spatial and temporal autocorrelation in the model learning process to assist with capturing the changes over time and tested the capabilities of the space-time random forest model by predicting drug-related activity hot zones. We focused particularly on crime incidents that involved heroin and synthetic drugs as these have been key drug types that have highly impacted cities during the opioid crisis in the U.S.

A randomized controlled trial of a brief behavioral intervention to reduce skin and soft tissue infections among people who inject drugs

BACKGROUND

People who inject drugs (PWID) are at high risk for skin and soft tissue infections (SSTIs), but few interventions have targeted their reduction. The goal of the current study was to test the effects of a brief skin and needle hygiene behavioral intervention (SKIN) in a two-group randomized controlled trial with 12-month follow-up.

METHOD

PWID (N = 252) were recruited from inpatient hospital units at a single urban medical center site and randomly assigned to an assessment-only (AO) condition or SKIN, which was a two-session intervention that included psychoeducation, behavioral skills demonstrations, and motivational interviewing. Mixed effects generalized linear models assessed the impact of the intervention on frequency of: 1) self-reported SSTIs, 2) uncleaned skin injections, and 3) injection.

RESULTS

Participants were 58.3 % male, 59.5 % White, and averaged 38 years of age. SKIN participants had 35 % fewer SSTIs compared to AO (p = .179), a difference of nearly one infection per year. The mean rate of uncleaned skin injections was about 66 % lower (IRR = 0.34, 95 % CI 0.20; 0.59, p < .001) among SKIN participants compared to AO. Almost one-third of participants reported no injection over follow-up and the mean rate of injection during follow-up was about 39 % lower (IRR = 0.61; 95 % CI 0.36; 1.02, p = .058) among persons randomized to SKIN than AO.

CONCLUSIONS

The SKIN intervention reduced uncleaned skin injections but did not reduce SSTIs significantly more than a control condition. Brief interventions can improve high-risk practices among PWID and lead to clinically meaningful outcomes.

Buprenorphine dispensing in an epicenter of the U.S. opioid epidemic: A case study of the rural risk environment in Appalachian Kentucky

BACKGROUND

Buprenorphine is a cornerstone to curbing opioid epidemics, but emerging data suggest that rural pharmacists in the US sometimes refuse to dispense this medication. We conducted a case study to explore buprenorphine dispensing practices in 12 rural Appalachian Kentucky counties, and analyze whether and how they were shaped by features of the rural risk environment.

METHODS

In this case study, we conducted one-on-one semi-structured interviews with 14 pharmacists operating 15 pharmacies in these counties to explore buprenorphine dispensing practices and perceived influences on these practices. Thematic analyses of the resulting transcripts revealed three features of the rural risk environment that shaped dispensing. To explore these three risk environment features, we analyzed policy documents (e.g., Attorney General lawsuits) and administrative databases (e.g., incarceration data). Textual documents were analyzed using thematic analyses and administrative data were analyzed using descriptive statistics; memoes explored relationships among risk environment features and dispensing practices.

RESULTS

Twelve of the 15 pharmacies limited dispensing, by refusing to serve new patients; limiting dispensing to known patients or prescribers; or refusing to dispense buprenorphine altogether. Concerns about exceeding a "Drug Enforcement Administration (DEA) cap" on opioid dispensing stifled dispensing. A legacy of aggressive and fraudulent marketing of opioid analgesics (OAs) by pharmaceutical companies and physician OA overprescribing undermined pharmacist trust in buprenorphine and in its prescribers. The escalating local war on drugs may have undermined dispensing by reinforcing stigma against people who use drugs.

CONCLUSIONS

Initiatives to increase buprenorphine prescribing must be accompanied by policy changes to increase dispensing. Specifically, buprenorphine should be removed from opioid monitoring systems; efforts to de-escalate the war on drugs should be extended to encompass rural areas; initiatives to dismantle aggressive OA marketing should be strengthened; and efforts to re-build pharmacist trust in physicians are needed.

Evidence for HIV transmission across key populations: a longitudinal analysis of HIV and AIDS rates among Black people who inject drugs and Black heterosexuals in 84 large U.S. metropolitan areas, 2008-2016

PURPOSE

To assess cross-population linkages in HIV/AIDS epidemics, we tested the hypothesis that the number of newly diagnosed AIDS cases among Black people who inject drugs (PWID) was positively related to the natural log of the rate of newly diagnosed HIV infections among Black non-PWID heterosexuals in 84 large U.S. metropolitan statistical areas (MSAs) in 2008-2016.

METHODS

We estimated a multilevel model centering the time-varying continuous exposures at baseline between the independent (Black PWID AIDS rates) and dependent (HIV diagnoses rate among Black heterosexuals) variables.

RESULTS

At MSA level, baseline (standardized β = 0.12) Black PWID AIDS rates and change in these rates over time (standardized β = 0.11) were positively associated with the log of new HIV diagnoses rates among Black heterosexuals. Thus, MSAs with Black PWID AIDS rates that were 1 standard deviation= higher at baseline also had rates of newly diagnosed HIV infections among Black non-PWID heterosexuals that were 10.3% higher. A 1 standard deviation increase in independent variable over time corresponded to a 7.8% increase in dependent variable.

CONCLUSIONS

Black PWID AIDS rates may predict HIV rates among non-PWID Black heterosexuals. Effective HIV programming may be predicated, in part, on addressing intertwining of HIV epidemics across populations.

Structural Determinants of Black MSM HIV Testing Coverage (2011-2016)

Over 30 years into the US HIV/AIDS epidemic, Black men who have sex with men (BMSM) continue to carry the highest burden of both HIV and AIDS cases. There is then, an urgent need to expand access to HIV prevention and treatment for all gay and bisexual men, underscoring the importance of the federal initiative 'Ending the Epidemic: A Plan for America'. This research examines structural factors associated with BMSM HIV testing coverage over time (2011-2016) in 85 US Metropolitan Statistical Areas (MSAs). We calculated MSA-specific annual measures of BMSM HIV testing coverage (2011-2016). Variables suggested by the Theory of Community Action (i.e., need, resource availability, institutional opposition and organized support) were analyzed as possible predictors of coverage using multilevel modeling. Relationships between BMSM HIV testing and the following covariates were positive: rates of BMSM living with HIV (b = 0.28), percent of Black residents employed (b = 0.19), Black heterosexual testing rate (b = 0.46), health expenditures per capita (b = 0.16), ACT UP organization presence in 1992 (b = 0.19), and syringe service presence (b = 0.12). Hard drug arrest rates at baseline (b = - 0.21) and change since baseline (b = - 0.10) were inversely associated with the outcome. Need, resources availability, organized support and institutional opposition are important determinants of place associated with BMSM HIV testing coverage. Efforts to reduce HIV incidence and lessen AIDS-related disparities among BMSM in the US require improved and innovative HIV prevention approaches directed toward BMSM including a fuller understanding of structural factors that may influence place variation in BMSM testing patterns and risk behavior in places of high need.

Hepatitis A Outbreaks Associated With the Opioid Epidemic in Kentucky Counties, 2017-2018

Objectives. To describe county-level socioeconomic profiles associated with Kentucky's 2017-2018 hepatitis A outbreak that predominately affected communities affected by the opioid epidemic.Methods. We linked county-level characteristics on socioeconomic and housing variables to counties' hepatitis A rates. Principal component analysis identified county profiles of poverty, education, disability, income inequality, grandparent responsibility, residential instability, and marital status. We used Poisson regression to estimate adjusted relative risks (RRs) and 95% confidence intervals (CIs).Results. Counties with scores reflecting an extremely disadvantaged profile (RR = 1.21; 95% CI = 0.99, 1.48) and greater percentage of nonmarried men, residential instability, and income inequality (RR = 1.15; 95% CI = 0.94, 1.41) had higher hepatitis A rates. Counties with scores reflecting more married adults, residential stability, and lower income inequality despite disability, poverty, and low education (RR = 0.77; 95% CI = 0.59, 1.00) had lower hepatitis A rates. Counties with a higher percentage of workers in the manufacturing industry had slightly lower rates (RR = 0.97; 95% CI = 0.94, 1.00).Conclusions. As expected, impoverished counties had higher hepatitis A rates. Evaluation across the socioeconomic patterns highlighted community-level factors (e.g., residential instability, income inequality, and social structures) that can be collected to augment hepatitis A data surveillance and used to identify higher-risk communities for targeted immunizations.

Relationship of Racial Residential Segregation to Newly Diagnosed Cases of HIV among Black Heterosexuals in US Metropolitan Areas, 2008-2015

Social science and public health literature has framed residential segregation as a potent structural determinant of the higher HIV burden among black heterosexuals, but empirical evidence has been limited. The purpose of this study is to test, for the first time, the association between racial segregation and newly diagnosed heterosexually acquired HIV cases among black adults and adolescents in 95 large US metropolitan statistical areas (MSAs) in 2008-2015. We operationalized racial segregation (the main exposure) using Massey and Denton's isolation index for black residents; the outcome was the rate of newly diagnosed HIV cases per 10,000 black adult heterosexuals. We tested the relationship of segregation to this outcome using multilevel multivariate models of longitudinal (2008-2015) MSA-level data, controlling for potential confounders and time. All covariates were lagged by 1 year and centered on baseline values. We preliminarily explored mediation of the focal relationship by inequalities in education, employment, and poverty rates. Segregation was positively associated with the outcome: a one standard deviation decrease in baseline isolation was associated with a 16.2% reduction in the rate of new HIV diagnoses; one standard deviation reduction in isolation over time was associated with 4.6% decrease in the outcome. Exploratory mediation analyses suggest that black/white socioeconomic inequality may mediate the relationship between segregation and HIV. Our study suggests that residential segregation may be a distal determinant of HIV among black heterosexuals. The findings further emphasize the need to address segregation as part of a comprehensive strategy to reduce racial inequities in HIV.

States with higher minimum wages have lower STI rates among women: Results of an ecological study of 66 US metropolitan areas, 2003-2015

Prior research has found that places and people that are more economically disadvantaged have higher rates and risks, respectively, of sexually transmitted infections (STIs). Economic disadvantages at the level of places and people, however, are themselves influenced by economic policies. To enhance the policy relevance of STI research, we explore, for the first time, the relationship between state-level minimum wage policies and STI rates among women in a cohort of 66 large metropolitan statistical areas (MSAs) in the US spanning 2003-2015. Our annual state-level minimum wage measure was adjusted for inflation and cost of living. STI outcomes (rates of primary and secondary syphilis, gonorrhea and chlamydia per 100,000 women) were obtained from the CDC. We used multivariable hierarchical linear models to test the hypothesis that higher minimum wages would be associated with lower STI rates. We preliminarily explored possible socioeconomic mediators of the minimum wage/STI relationship (e.g., MSA-level rates of poverty, employment, and incarceration). We found that a $1 increase in the price-adjusted minimum wage over time was associated with a 19.7% decrease in syphilis rates among women and with an 8.5% drop in gonorrhea rates among women. The association between minimum wage and chlamydia rates did not meet our cutpoint for substantive significance. Preliminary mediation analyses suggest that MSA-level employment among women may mediate the relationship between minimum wage and gonorrhea. Consistent with an emerging body of research on minimum wage and health, our findings suggest that increasing the minimum wage may have a protective effect on STI rates among women. If other studies support this finding, public health strategies to reduce STIs among women should include advocating for a higher minimum wage.

Identifying Which Place Characteristics are Associated with the Odds of Recent HIV Testing in a Large Sample of People Who Inject Drugs in 19 US Metropolitan Areas

This exploratory analysis investigates relationships of place characteristics to HIV testing among people who inject drugs (PWID). We used CDC's 2012 National HIV Behavioral Surveillance (NHBS) data among PWID from 19 US metropolitan statistical areas (MSAs); we restricted the analytic sample to PWID self-reporting being HIV negative (N = 7477). Administrative data were analyzed to describe the 1. Sociodemographic Composition; 2. Economic disadvantage; 3. Healthcare Service/Law enforcement; and 4. HIV burden of the ZIP codes, counties, and MSAs where PWID lived. Multilevel models tested associations of place characteristics with HIV testing. Fifty-eight percent of PWID reported past-year testing. MSA-level per capita correctional expenditures were positively associated with recent HIV testing among black PWID, but not white PWID. Higher MSA-level household income and imbalanced sex ratios (more women than men) in the MSA were associated with higher odds of testing. HIV screening for PWID is suboptimal (58%) and needs improvement. Identifying place characteristics associated with testing among PWID can strengthen service allocation and interventions in areas of need to increase access to HIV testing.

Place Still Matters: Racial/Ethnic and Geographic Disparities in HIV Transmission and Disease Burden

Neighborhood-level structural interventions are needed to address HIV/AIDS in highly affected areas. To develop these interventions, we need a better understanding of contextual factors that drive the pandemic. We used multinomial logistic regression models to examine the relationship between census tract of current residence and mode of HIV transmission among HIV-positive cases. Compared to the predominantly white high HIV prevalence tract, both the predominantly black high and low HIV prevalence tracts had greater odds of transmission via injection drug use and heterosexual contact than male-to-male sexual contact. After adjusting for current age, gender, race/ethnicity, insurance status, and most recently recorded CD4 count, there was no statistically significant difference in mode of HIV transmission by census tract. However, heterosexual transmission and injection drug use remain key concerns for underserved populations. Blacks were seven times more likely than whites to have heterosexual versus male-to-male sexual contact. Those who had Medicaid or were uninsured (versus private insurance) were 23 and 14 times more likely, respectively, to have injection drug use than male-to-male sexual contact and 10 times more likely to have heterosexual contact than male-to-male sexual contact. These findings can inform larger studies for the development of neighborhood-level structural interventions.