Comparing respondent-driven sampling and targeted sampling methods of recruiting injection drug users in San Francisco

Modeling the impact of the COVID-19 pandemic on achieving HCV elimination amongst young and unstably housed people who inject drugs in San Francisco

BACKGROUND

Young adult (18-30 years) people who inject drugs (PWID) face high hepatitis C virus (HCV) prevalence. In San Francisco, where >60% of PWID lack stable housing, barriers hinder HCV treatment access. We assessed progress towards the World Health Organization's (WHO) HCV elimination goal of an 80% reduction in incidence over 2015-2030, focusing on young (YPWID) and unstably housed PWID in San Francisco.

METHODS

We developed a dynamic HCV transmission model among PWID, parameterized and calibrated using bio-behavioural survey datasets from San Francisco. This included 2018 estimates for the antibody-prevalence among PWID (77%) and care cascade estimates for HCV for YPWID (72% aware of their status and 33% ever initiating treatment). Based on programmatic data, we assumed a 53.8% reduction in testing and 40.7% decrease in treatment from 2020 due to the COVID-19 pandemic, which partially rebounded from April 2021 with testing rates then being 31.1% lower than pre-pandemic rates and treatment numbers being 19.5% lower. We simulated different scenarios of how services changed after the pandemic to project whether elimination goals would be met.

RESULTS

Continuing post-pandemic rates of testing and treatment, the model projects an 83.3% (95% credibility interval [95% CrI]:60.6-96.9%) decrease in incidence among PWID over 2015-2030 to 1.5/100pyrs (95% CrI:0.3-4.4) in 2030. The probability of achieving the elimination goal by 2030 is 62.0%. Among YPWID and unstably housed PWID, the probability of achieving the elimination goal by 2030 is 54.8 and 67.6%, respectively. Importantly, further increasing testing and treatment rates to pre-pandemic levels by 2025 only results in a small increase in the probability (67.5%) of the elimination goal being achieved among all PWID by 2030, while increased coverage of medication for opioid use disorder among YPWID and/or housing interventions results in the probability of achieving elimination increasing to over 75%.

CONCLUSION

The COVID-19 pandemic impeded progress toward achieving HCV elimination. Our findings indicate that existing partial rebounds in HCV testing and treatment may achieve the elimination goal by 2030, with an additional scale-up of interventions aimed at YPWID or unstably housed PWID ensuring San Francisco is likely to achieve elimination by 2030.

Peer-to-Peer Chain Recruitment for Enrolling Young South African Women into an HIV Pre-exposure Prophylaxis (PrEP) Intervention Study: How Did It Perform?

Peer-to-peer chain recruitment has been used for descriptive studies, but few intervention studies have employed it. We used this method to enroll sexually active women ages 18 to 25 into an online Pre-Exposure Prophylaxis (PrEP) information and motivation intervention pilot in eThekwini (Durban), South Africa. Seeds (N = 16) were recruited by study staff and randomized to Masibambane, Ladies Chat, a Gender-Enhanced group-based WhatsApp Workshop (GE), or Individual-Access (IA), a control condition that provided participants with online information/motivation materials only. Each seed could recruit up to three women to participate in the same study condition, with an incentive for each enrolled woman; participants in subsequent waves could choose to recruit or not. We evaluated if peer-to-peer recruitment was self-sustaining and resulted in enrolling women who, in subsequent waves, had less contact with the health care system and less knowledge about PrEP than the initial seeds. Over three recruitment waves beyond the seeds, 84 women were recruited. Almost 90% of women became recruiters, with each recruiting on average 1.90 women and 1.26 eligible enrolled women. The approach was successful at reaching women with less education but not women with less health system contact and PrEP knowledge across waves. IA participants had a slightly higher, though non-significantly different, percentage of individuals who became Peer Health Advocates (PHAs) than GE participants and, on average, they recruited slightly more women who enrolled. Our findings demonstrated that peer-to-peer recruitment is a feasible and self-sustaining way to recruit SA young women into a PrEP intervention study.

Characterizing Opioid Withdrawal Experiences and Consequences Among a Community Sample of People Who Use Opioids

BACKGROUND

Opioid withdrawal symptoms are a highly salient and consequential health condition experienced by people who use opioids (PWUO). This study utilized qualitative interviews to explore opioid withdrawal experiences and consequences among PWUO in Los Angeles County, USA.

METHODS

Semi-structured qualitative interviews were conducted with 22 PWUO (aged 27-63 years) between May 2021 and May 2022. Participants self-reported opioid and injection drug use in the last 30 days. We employed an inductive thematic approach to systematically code and synthesize textual interview data.

RESULTS

Participants experienced withdrawal symptoms frequently, with many going to great lengths to avoid them. Withdrawal pain was described as incapacitating and interfered with PWUO's ability to sustain regular employment and ensure stable housing. Avoiding withdrawal was described as influential in driving decisions to continue using opioids. Mechanisms for managing withdrawal included using other substances to the point of sedation. PWUO who transitioned from heroin to fentanyl use revealed more frequent, painful, and faster onset of withdrawal symptoms. Adverse withdrawal experiences and fear of precipitated withdrawal from buprenorphine were barriers to treatment initiation and continuation.

CONCLUSION

Withdrawal symptoms among PWUO increase health risk. Improved strategies to treat opioid withdrawal are urgently needed. Solutions such as safe supply and intentional opioid withdrawal interventions (educational trainings, withdrawal comfort kits) are needed to improve withdrawal management and reduce opioid-related harm.

Estimating Hidden Population Size of COVID-19 using Respondent-Driven Sampling Method - A Systematic Review

INTRODUCTION

Currently, the ongoing COVID-19 pandemic is posing a challenge to health systems worldwide. Unfortunately, the true number of infections is underestimated due to the existence of a vast number of asymptomatic infected individual's proportion. Detecting the actual number of COVID-19-affected patients is critical in order to treat and prevent it. Sampling of such populations, so-called hidden or hard-to-reach populations, is not possible using conventional sampling methods. The objective of this research is to estimate the hidden population size of COVID-19 by using respondent-driven sampling (RDS) methods.

METHODS

This study is a systematic review. We have searched online databases of PubMed, Web of Science, Scopus, Embase, and Cochrane to identify English articles published from the beginning of December 2019 to December 2022 using purpose-related keywords. The complete texts of the final chosen articles were thoroughly reviewed, and the significant findings are condensed and presented in the table.

RESULTS

Of the 7 included articles, all were conducted to estimate the actual extent of COVID-19 prevalence in their region and provide a mathematical model to estimate the asymptomatic and undetected cases of COVID-19 amid the pandemic. Two studies stated that the prevalence of COVID-19 in their sample population was 2.6% and 2.4% in Sierra Leone and Austria, respectively. In addition, four studies stated that the actual numbers of infected cases in their sample population were significantly higher, ranging from two to 50 times higher than the recorded reports.

CONCLUSIONS

In general, our study illustrates the efficacy of RDS in the estimation of undetected asymptomatic cases with high cost-effectiveness due to its relatively trouble-free and low-cost methods of sampling the population. This method would be valuable in probable future epidemics.

Prevalence and factors associated with neck injection among people who inject drugs in San Francisco, California

BACKGROUND

Groin and neck injections are generally a last resort for people who inject drugs (PWID) who do not have easy access to functioning veins. These alternative injection practices can lead to an increased likelihood of adverse health outcomes. There is still much we do not know about groin and neck injections among PWID in the US, as the literature to-date comes from studies primarily focused on groin injections outside the US. We assessed prevalence, predictors, and associated behaviors of neck injection through a survey fielded in San Francisco, California, US.

METHODS

The sample comes from a longitudinal observational study that used targeted sampling to recruit PWID in San Francisco. The current study sample includes 239 PWID who completed their 12-month survey between June 2019 and June 2020.

RESULTS

About a third of the sample reported injecting in their neck in the past 30 days, with the most common reason being lack of available veins. Age, past 6-month abscess / soft tissue infection, and past 30-day use of opioids mixed with cocaine were significantly associated with past 30-day neck injection in the final multivariate model. Past 30-day neck injection was also significantly associated with being injected by another person in the past 30 days.

CONCLUSIONS

PWID at higher risk for vein deterioration were more likely to inject into their neck. Harm reduction strategies such as safer injection counseling, safe smoking supplies, use of "street doctors," and safe consumption sites may reduce instances of neck injection and/or associated health risks.

Reduced Emergency Department Visits and Hospitalisation with Use of an Unsanctioned Safe Consumption Site for Injection Drug Use in the United States

BACKGROUND

Safe consumption sites (SCS) are an evidence-based intervention to prevent drug use-related harm. In late 2014, an organisation in an undisclosed location in the USA opened an unsanctioned SCS.

OBJECTIVE

To evaluate whether use of the unsanctioned SCS affected medical outcomes.

DESIGN

A prospective cohort study.

SETTING

Neighbourhoods surrounding the SCS.

PARTICIPANTS

People who injected drugs were recruited and interviewed at baseline and 6 and 12 months from 2018 to 2020.

INTERVENTION

People using the SCS could bring pre-obtained drugs to consume via injection, which were monitored by trained staff with naloxone.

MAIN MEASURES

Any overdose, number of non-fatal overdoses, skin and soft tissue infections, emergency department utilisation, number of emergency department visits, hospitalisation and number of nights spent in hospital.

KEY RESULTS

A total of 494 participants enrolled in the study; 59 (12%) used the SCS at least once. We used propensity score weighting to analyse the association between SCS utilisation and measures. People using the SCS were 27% (95% CI: 12-46%) less likely to visit the emergency department, had 54% (95% CI: 33-71%) fewer emergency department visits, were 32% (95% CI: 4-57%) less likely to be hospitalised, and spent 50% (95% CI: 1-85%) fewer nights in hospital. Though not significant, people using the SCS had a lower likelihood of overdosing and slightly higher likelihood of skin and soft tissue infections.

CONCLUSIONS

Our findings support the use of SCS in the USA to reduce the growing burden of acute care service utilisation related to injection drug use.

Disparities in Sexually Transmitted Infection Testing and the Need to Strengthen Comprehensive Sexual Health Services for Trans Women

Purpose

Few studies have examined the importance of improving the sexual health delivery system beyond HIV among trans women. We assessed survey data from the National HIV Behavioral Surveillance Transgender Woman (NHBS-Trans) Study in San Francisco to characterize the utilization of sexual health services among HIV-negative trans women and to explore opportunities to improve sexual health services for trans women.

Methods

Trans women were recruited through respondent-driven sampling from July 2019 to February 2020. The analytic sample was restricted to 116 HIV-negative trans women. We identified trends in data using chi-squared tests to assess significance between sexual risk behavior and the use of preventative sexual health services and built logistic regression models to assess the relationships between sexual risk behaviors and sexually transmitted infection (STI) testing.

Results

The majority of sample was trans women of color with most identifying as Latinx (42.2%). Over half were low income (56%), and majority had been homeless in past 12 months (62.9%). The prevalence of condomless receptive anal sex was 52.6% with about two-thirds (62.1%) recently having an STI test. Participants who engaged in recent condomless receptive anal sex had more than fivefold greater odds of having a recent STI test compared to their counterparts who did not (adjusted odds ratio [aOR] 5.60, 95% confidence interval [CI] 1.83-17.11; p=0.003). We also found age- and education-related disparities in STI testing.

Conclusion

This study characterized the utilization of sexual health services among HIV-negative trans women and identified important disparities in STI testing. We discuss opportunities to strengthen sexual health care delivery systems.

Health risk associated with residential relocation among people who inject drugs in Los Angeles and San Francisco, CA: a cross sectional study

Background

Given the housing instability and frequent residential relocation (both volitional and hegemonic) of people who inject drugs, we sought to determine whether residential relocation (defined as sleeping in a different place in the past 30 days) is associated with health outcomes in a sample of people who inject drugs (PWID).

Methods

We recruited 601 PWID using targeted sampling and interviewed them between 2016 and 2018 in San Francisco and Los Angeles, CA about housing, drug use practices, and service utilization. We then developed multivariable regression models to investigate how residential relocation is associated with violence, health outcomes, and social service access. We analyzed our data between June 2018 and October 2019.

Results

Participants who relocated in the past 30 days had lower odds of being in substance use treatment (Adjusted Odds Ratio [AOR] = 0.62, 95% Confidence Interval [CI] = 0.42, 0.89) and higher odds of nonfatal overdose (AOR = 2.50, CI = 1.28, 4.90), receptive syringe sharing (AOR = 2.26, CI = 1.18, 4.32), severe food insecurity (AOR = 1.69, CI = 1.14, 2.50), having belongings stolen (AOR = 2.14, CI = 1.42, 3.21), experiencing physical assault (AOR = 1.58, CI = 1.03, 2.43), arrest (AOR = 1.64, CI = 1.02, 2.65), and jail (AOR = 1.90, CI = 1.16, 3.13) in the past 6 months when compared to those who did not relocate.

Conclusions

PWID who have relocated in the past 30 days have higher odds of experiencing violence and life- threatening adverse outcomes, and policies that disrupt living circumstances of PWID should be ended in favor of those that support housing stability.

Predictors of protein intake among people who inject drugs in Los Angeles and San Francisco, California

BACKGROUND AND OBJECTIVES

While inadequate nutrition can weaken the immune system and lead to negative health sequelae for vulnerable populations, little is known about nutritional intake among people who inject drugs (PWID). We aimed to quantify nutritional intake among PWID and to explore associations between protein intake and drug use.

METHODS

A cross-sectional design was used to analyze self-reported participant data. PWID were recruited from community settings in California in 2016/2017. Participants reported on food consumption per day for a 30-day period, from which a continuous protein intake variable was created.

RESULTS

Modal characteristics of participants (N = 937) were: white (42.5%), male (75.3%), healthy body mass index (BMI) (56.6%), and unhoused (82.9%). Less than 1% of participants met or exceeded recommended guidelines for protein intake (0.80 g/day/1 kg body weight). The final multiple regression model found protein intake to be significantly positively associated with older age, high school or greater education, frequency of opiate and marijuana use, while Latinx ethnicity was inversely associated with protein intake, adjusting for gender.

DISCUSSION AND CONCLUSIONS

Our study shows PWID are generally not underweight, yet they are grossly protein deficient, which can be harder to recognize. Poverty, homelessness, and other structural barriers likely contribute to this issue, which demonstrates the need for communities to provide more access to nutrient-rich food to PWID.

SCIENTIFIC SIGNIFICANCE

Our study demonstrates the novel findings that opiate and marijuana use frequency, but not stimulants (methamphetamine and cocaine) may increase preference for protein-rich foods among PWID.

Effect of an Unsanctioned Safe Consumption Site in the United States on Syringe Sharing, Rushed Injections, and Isolated Injection Drug Use: A Longitudinal Cohort Analysis

BACKGROUND

HIV and other medical complications of drug use, including overdose, are rising among people who inject drugs in the United States (US). Risk of complications and mortality increase with injection behaviors such as syringe sharing, rushing injections, and injecting in isolated places. Studies suggest safe consumption sites (SCS) reduce high-risk injection behaviors by offering sterile syringes and a safe, supervised space to consume drugs, although this has yet to be evaluated in the US.

SETTING

An unsanctioned SCS in an undisclosed US location.

METHODS

From 2018 to 2019, we recruited people who inject drugs using targeted sampling methods (N = 494) and conducted interviews at baseline, 6-, and 12-months. We sought to determine associations of past-month SCS use with past-month receptive syringe sharing, rushed injections, and injections in isolated places. We analyzed data using inverse probability of treatment weighted Poisson regression models. Generalized estimating equations accounted for repeated measures.

RESULTS

Fifty-two (11%) participants had past-month SCS use. Participants with past-month SCS use had decreased rates of receptive syringe sharing (Incident rate ratio [IRR] 0.17, 95% CI: 0.03 to 1.02) and injecting in an isolated location (IRR 0.77, 95% CI: 0.54 to 1.27) compared with those without past-month SCS use, although results were not statistically conclusive. Rate of rushed injections was only slightly lower (IRR 0.94, 95% CI: 0.70 to 1.30).

CONCLUSION

SCS may show benefit in reducing high-risk injection practices, and legal sanctioning of an SCS may offer further advantages. SCS implementation should be considered to help reduce the spread of HIV, overdose mortality, and prevent other medical complications of injection drug use.

Improved syringe disposal practices associated with unsanctioned safe consumption site use: A cohort study of people who inject drugs in the United States

BACKGROUND

Community opposition to safe consumption sites often centers around improper syringe disposal. People are concerned these sites might attract people who inject drugs to the neighborhood, which might in turn lead to more used syringes left in public settings.

METHODS

We evaluated an unsanctioned safe consumption site in an undisclosed United States city in 2018-2020 to assess whether use of the site was associated with improper syringe disposal practices. We recruited people who inject drugs (N=494) using targeted sampling methods, and interviewed participants at baseline, 6 months, and 12 months. We employed a quasi-experimental design involving inverse probability of treatment weighting using propensity scores. We used generalized estimating equations and Poisson models to calculate relative risk and incidence rate ratios of improper syringe disposal.

RESULTS

The risk of any improper syringe disposal was comparable among people who used and did not use the unsanctioned safe consumption site in prior 30 days (relative risk 1.03; 95% confidence interval=0.53, 1.17). The rate of improperly disposed syringes per number of injections in prior 30 days was significantly lower among people who had used the unsanctioned safe consumption site during the same period (incident rate ratio 0.42; 95% confidence interval=0.18, 0.88).

CONCLUSION

When people used this unsanctioned safe consumption site, they disposed of significantly fewer syringes in public places, including streets, sidewalks, parks, or parking lots, than people not using the site. This study helps allay concerns that implementing safe consumption sites in the US would lead to increases in improperly disposed syringes.

Social Stability and Unmet Health Care Needs in a Community-Based Sample of Women Who Use Drugs

Objective

To examine the relationship between social stability and access to healthcare services among a community-based sample of adult female drug users.

Methods

We developed a measure of social stability and examined its relationship to health care access. Data came from a cross-sectional sample of female drug users (N = 538) in Oakland, CA who were interviewed between September 2014 and August 2015. We categorized women as having low (1-5), medium (6-10), or high (11-16) social stability based on the tertile of the index sample distribution. We then used ordered logistic regression to examine the relationship between social stability and self-reported access to mental health services and medical care.

Results

Compared with women in the low stability group, those with high stability experienced a 58% decline in the odds of needed but unmet mental health services [AOR: 0.42; 95% C.I.: 0.26, 0.69] and a 68% decline in the odds of unmet medical care [AOR: 0.32; 95% C.I.: 0.19, 0.54] after adjusting for confounders. The coefficients we observed reduced in size at higher levels of the stability index suggesting a positive association between social experiences and access to healthcare services.

Conclusion

Women who use drugs are at increased risk of adverse health outcomes and often experience high levels of unmet healthcare needs. Our study highlights the importance of addressing social determinants of health and suggests that improving social factors such as housing stability and personal safety may support access to healthcare among female drug users.

Factors associated with injury and blood-borne infection risk when providing assisted injection among people who inject drugs

OBJECTIVE

Prior research has associated assisted injection with risk behaviors, but other risks such as injury, missed veins, and incidental exposures to blood-borne infections during an injection episode have not been assessed. In the following, we present the frequency of these other risks and determine factors associated with missing a vein and incidental blood exposure among people who inject drugs (PWID).

METHODS

We conducted a cross-sectional analysis of data from PWID who were recruited using targeted sampling in Los Angeles and San Francisco, California, during 2016 and 2017. The analytic sample consist of 336 participants who reported providing injection assistance in the last 6 months. Multivariate logistic regression models were developed for reporting the following risks: missing a vein; getting the recipient's blood on the injection provider; and getting blood on clothes or surfaces.

RESULTS

In the last 6 months, the most common negative consequences were getting blood on clothes or surfaces (40%), getting the recipient's blood on the injection provider (23%), and missing a vein (17%). In multivariate logistic regression analysis, missing the vein was significantly associated with higher odds of assisting a leg injection while getting the injection recipient's blood on the provider or getting blood on clothes or nearby surfaces was associated with higher odds of assisting a groin injection injecting in the groin.

CONCLUSION

Providing injection assistance can result in incidental blood exposures and injury, particularly when injecting in sensitive locations on the body. Harm reduction interventions to reduce risks associated with this practice are essential to improving the well-being of PWID.

Consuming illicit opioids during a drug overdose epidemic: Illicit fentanyls, drug discernment, and the radical transformation of the illicit opioid market

BACKGROUND

North America continues to face an opioid overdose epidemic, driven by persistent increases in illicit fentanyls and fluctuations in potency leading to uncertainty for consumers. This qualitative study was conducted to better understand how people who inject drugs (PWID) came to recognize fentanyl as a growing adulterant of heroin and the subsequent sensory discernment strategies they employed to continue injecting. Our main objective was to investigate how observations and knowledge are combined as homegrown techniques for detecting fentanyl and minimizing risk. Secondary objectives were to examine the impact of growing fentanyl adulteration on individual drug use behavior.

METHODS

Between April and May 2019, 28 PWID (18 men, 10 women; average age = 38.43 years, SD = 9.26) were purposely recruited from a needle services program in Greensboro, North Carolina. Study participants were interviewed in-person using a qualitative, semi-structured instrument. Interviews were analyzed with a general inductive approach using NVivo12.

RESULTS

Participants described methods for detecting fentanyl in illicit opioids. Sudden increases in the potency of the 'rush' and sharp decreases in the length of the 'high' were chief indicators along with changes in drug color and texture. Heavy sedation was associated with fentanyl use and histamine-releasing effects characterized as 'pins and needles' were ascribed to injecting fentanyl as a component of the rush. Fentanyl's short high helped explain higher injection frequency and heavy sedation was the leading reason for co-using fentanyl with cocaine/crack or methamphetamine.

CONCLUSION

PWID have the capacity to recognize changes to the illicit opioid supply. Study participants navigated unpredictable fluctuations in the illicit opioid market by employing homegrown discernment techniques, modifying drug use behavior, and co-using non-opioid drugs. Researchers and policymakers should involve PWID as subject matter experts to help modernize harm reduction for the fentanyl age with practical strategies to boost resiliency and save lives.

Transition from injecting opioids to smoking fentanyl in San Francisco, California

BACKGROUND

The introduction of illicitly made fentanyl in the United States has slowly replaced heroin. New illicit drugs are often associated with changes in frequency and modes of administration. We assessed changes in injection frequency and smoking fentanyl in the new era of fentanyl availability in San Francisco.

METHODS

We used targeted sampling to recruit 395 people who inject drugs (PWID) into an observational cohort study in San Francisco 2018-2020. We assessed changes in injection frequency, opioid injection frequency and fentanyl smoking frequency in four six-month periods. We also conducted qualitative interviews with PWID asking about motivations for injecting and smoking opioids.

RESULTS

The median number of past-month injections steadily decreased by semi-annual calendar year from 92 injections in July to December 2018 to 17 injections in January to June 2020. The rate of opioid injections reduced by half (Adjusted Incidence Rate Ratio = 0.41; 95 % Confidence Interval = 0.25, 0.70; p < 0.01). The number of days smoking fentanyl was associated with fewer number of injections (X2(2) = 11.0; p < 0.01). Qualitative interviews revealed that PWID's motivation for switching from injecting tar heroin to smoking fentanyl was related to difficulties accessing veins. After switching to smoking fentanyl, they noticed many benefits including how the drug felt, improved health, fewer financial constraints, and reduced stigma.

CONCLUSION

Between 2018 and 2020, there was a shift from injecting tar heroin to smoking fentanyl in San Francisco. Reductions in injection of illicit drugs may offer public health benefit if it reduces risk of blood-borne viruses, abscesses and soft-tissue infections, and infective endocarditis.

Prevalence and predictors of recent temporary psychiatric hold among a cohort of people who inject drugs in Los Angeles and San Francisco, California

California's Welfare and Institutions code 5150 allows for a temporary psychiatric hold (TPH) of individuals who present a danger to themselves or others and/or may be gravely disabled due to mental illness. Little is known about the frequency and predictors of involuntary holds among people who inject drugs (PWID).

METHODS

We sought to identify the prevalence and predictors of recent TPHs (within the past 12 months) among a community-recruited sample of PWID in Los Angeles and San Francisco, California during 2017-2018 (N = 531). Multivariable logistic regression modeling was used to evaluate demographic (e.g., age), economic (e.g., homelessness), drug use (e.g., types of drugs used), incarceration (e.g., recent arrest history) and mental health (e.g., lifetime mental health diagnosis) variables associated with recent TPH.

RESULTS

Age (40-49 years old vs age 50 or older: AOR = 5.85; 95 % CI = 2.18, 15.67), current homelessness (AOR = 3.75; 95 % CI = 1.28, 11.0), lifetime mental health history (AOR = 6.23; 95 % CI = 2.08, 18.66), and frequency of methamphetamine use (AOR = 1.01; 95 % CI = 1.00, 1.01) were statistically associated with increased odds of having experienced a TPH, while frequency of past month heroin/opioid use was associated with decreased odds of reporting a TPH (AOR = 0.99; 95 % CI = 0.99, 1.00) in multivariable analysis.

CONCLUSIONS

Diverse factors were associated with TPH among PWID. Our analysis underscores the need for research on PWID with co-occurring substance-use and mental illness disorders and homelessness. There is urgent need for expanding access to lower barrier publicly funded mental health treatment from a harm-reduction approach.

The naloxone delivery cascade: Identifying disparities in access to naloxone among people who inject drugs in Los Angeles and San Francisco, CA

BACKGROUND

Opioid overdoses are a leading cause of injury death in the United States. Providing people who inject drugs (PWID) with naloxone is essential to preventing deaths. However, research regarding gaps in naloxone delivery is limited.

METHODS

We interviewed 536 PWID in San Francisco and Los Angeles, California from 2017 to 2018. We described naloxone engagement and re-engagement cascades, and identified factors associated with receiving naloxone in the past six months and currently owning naloxone.

RESULTS

The engagement cascade showed 72 % of PWID ever received naloxone, 49 % received it in the past six months, and 35 % currently owned naloxone. The re-engagement cascade showed, among PWID who received naloxone in the past six months, 74 % used and/or lost naloxone, and 67 % refilled naloxone. In multivariable analyses, identifying as Latinx (aRR = 0.53; 95 % CI: 0.39, 0.72) and Black (aRR = 0.73; 95 % CI: 0.57, 0.94) vs White were negatively associated with receiving naloxone in the past six months, while using opioids 1-29 times (aRR = 1.35; 95 % CI: 1.04, 1.75) and 30+ times (aRR = 1.52; 95 % CI: 1.17, 1.99) vs zero times in the past 30 days and witnessing an overdose in the past six months (aRR = 1.69; 95 % CI: 1.37, 2.08) were positively associated with receiving naloxone in the past six months. In multivariable analyses, being unhoused vs housed (aRR = 0.82; 95 % CI: 0.68, 0.99) was negatively associated with currently owning naloxone.

CONCLUSIONS

Our study adds to the literature by developing naloxone engagement and re-engagement cascades to identify disparities. Naloxone scale-up should engage populations facing inequitable access, including people of color and those experiencing homelessness.

How to improve diversity in patient and public involvement

Patient and public involvement involves ascertaining the opinions of and collaborating with patients and members of the public to holistically improve the quality of research. Patient and public involvement provides patients with a platform to use and share their lived experiences. This allows healthcare professionals to gain a deeper appreciation of the patient's perspective, which enables future research to be more patient centred and tailored to patients' requirements. Patient and public involvement aims to broadly encapsulate the opinions of the public, so ensuring diversity is recommended. This article provides a practical framework to increase diversity and engage hard-to-reach demographics in patient and public involvement. It highlights some common barriers to participation and methods for overcoming this, describes sampling frameworks and provides examples of how these have been adopted in practice.

Factors associated with methamphetamine withdrawal symptoms among people who inject drugs

BACKGROUND

Regular methamphetamine (MA) use can result in withdrawal syndrome characterized by fatigue, agitation, depression, and anxiety. No studies that we are aware of have examined the prevalence and predictors of MA withdrawal symptoms among people who inject drugs (PWID).

METHODS

PWID were recruited using targeted sampling methods in Los Angeles and San Francisco, California from 2016 to 2017. Survey questions included demographics, drug use, and MA withdrawal symptoms, frequency, and symptom severity. Participants who reported regular MA use (> 12 times in the last 30 days) were included in this analysis (N = 595). Multivariable regression models were developed to examine factors associated with any MA withdrawal, withdrawal frequency, symptom severity, and receptive syringe sharing.

RESULTS

MA withdrawal symptoms in the past 6 months were reported by 53 % of PWID, with 25 % reporting weekly withdrawal symptoms, and 20 % reporting very or extremely painful symptoms. In multivariable logistic regression, presence of any MA withdrawal symptoms was positively associated with more frequent MA use and non-injection tranquilizer use and inversely associated with crack cocaine use. Among those reporting any withdrawal, female sex was associated with more frequent withdrawal symptoms. Very or extremely painful withdrawal symptoms were associated with being in residential treatment. Receptive syringe sharing was associated with any MA withdrawal symptoms and weekly frequency of symptoms.

CONCLUSION

MA withdrawal symptoms are common among PWID and are associated with receptive syringe sharing. Strategies for implementing MA use treatment, safe supply programs, and syringe services programs targeting people who inject MA are indicated.

Correlates of Transactional Sex and Violent Victimization among Men Who Inject Drugs in Los Angeles and San Francisco, California

Men who inject drugs (MWID) and engage in transactional sex (i.e., receive money or drugs in exchange for sex) are vulnerable to HIV and violence. However, MWID who engage in transactional sex have been less studied than women. We examine factors associated with transactional sex among MWID in Los Angeles and San Francisco and whether transactional sex is associated with violent victimization. MWID were recruited using targeted sampling methods in 2011-2013 and completed surveys that covered demographics, drug use, HIV risk, violence, transactional sex, and other items. Multivariable logistic regression was used to (1) determine factors independently associated with transactional sex and (2) determine if transactional sex was independently associated with violence victimization in the last 6 months among MWID. An interaction term between income source and sexual identity was included in the transactional sex model. Of the 572 male PWID in the sample, 47 (8%) reported transactional sex in the past 6 months. Self-reported HIV infection was 7% for MWID who did not report transactional sex, 17% for MWID who reported transactional sex, and 24% for MWID who reported transactional sex and reported gay or bisexual identity. In multivariable analysis, transactional sex was positively associated with gay or bisexual identity (GB without illegal income adjusted odds ratio [AOR] = 5.16; 95% confidence interval [CI] = 1.86-14.27; GB with illegal income AOR = 13.55, CI = 4.57-40.13), coerced sex in the last 12 months (AOR = 11.66, CI = 1.94-70.12), and violent victimization in the last 12 months (AOR = 2.31, CI = 1.13-4.75). Transactional sex was negatively associated with heroin injection (last 30 days) (AOR = 0.37; 95% CI = 0.18-0.78). Transactional sex was independently associated with violent victimization in the last 12 months (AOR = 2.04; 95% CI = 1.00-4.14) while controlling for confounders. MWID who engaged in transactional sex are at elevated risk for HIV and multiple forms of violent victimization. Interventions focused on this at-risk subpopulation are urgently needed and should include access to substance use disorder treatment, victimization services, and harm reduction services across the HIV care continuum.

Factors associated with health-related cannabis use intentions among a community sample of people who inject drugs in Los Angeles and San Francisco, CA 2016 to 2018

OBJECTIVE

Cannabis motivations have been studied extensively among patients of medicinal cannabis dispensaries, but less is known about motivations in community samples of opioid-using people who inject drugs. Our objective is to describe cannabis use motivations associated with self-treatment of physical pain, emotional issues, and as an opioid substitute.

METHODS

Data come from 6-month follow-up interviews with people who inject drugs who participated in a study on the efficacy of an injection initiation prevention intervention in Los Angeles and San Francisco, California from 2016-18. The analytic sample consists of 387 people who inject drugs who reported past-month cannabis use. We developed multivariable logistic regression models by reported cannabis use motivations: physical pain relief, emotional problems, and opioid substitute.

RESULTS

The most common cannabis use motivations reported by people who inject drugs was to "get high," relieve physical pain and emotional problems, and reduce opioid use. In separate multivariate models, using cannabis for physical pain relief was associated with higher odds of using cannabis as a substitute for opioids; cannabis for emotional problems was associated with being diagnosed with depression; and cannabis as a substitute for opioids was associated with non-prescribed, non-injection methadone use.

CONCLUSION

People who inject drugs reported using cannabis for health-related motivations. This motivation aligns with health needs and suggests the acceptability of cannabis use for health reasons in this population. Studies to determine the medical effectiveness of cannabis products for these common health and mental health needs among people who inject drugs are needed.

Co-use of methamphetamine and opioids among people in treatment in Oregon: A qualitative examination of interrelated structural, community, and individual-level factors

BACKGROUND

Rates of methamphetamine use and methamphetamine-related deaths have increased steadily in the United States in recent years. Methamphetamine is increasingly present in opioid-related deaths. An initial study of de-identified urine specimens (n = 102) collected at a drug treatment program between 2017 and 2018 indicated that 61% of specimens contained methamphetamine; of the specimens containing methamphetamine, people were, on average, five years younger than those who tested negative for methamphetamine; and non-fentanyl opioids were more than three times as common in methamphetamine positive specimens. The National Drug Early Warning System (NDEWS) Coordinating Center initiated a HotSpot Study to assess whether there was an emerging dynamic in the area, or if enhanced data collection could give insights into the co-use of methamphetamine and opioids.

METHODS

A qualitative study, grounded in principles of rapid ethnographic assessment and a social science/anthropological framework was conducted and used methodological complementarity to contextualize results from the initial urinalysis study. Targeted sampling was conducted at two treatment sites. Program staff and patients were recruited to participate in focus groups and semi-structured interviews to assess structural, community, and individual-level factors impacting methamphetamine and opioid co-use.

RESULTS

Within our broader framework of structural, community, and individual-level factors intersecting co-use, our data yielded three sub-themes: 1) the circulation of stigma regarding methamphetamine use was consistently described by both patients and staff and this intersected structural changes in treatment policy and suggested compounded stigma; 2) community-level factors and temporality were important for understanding patterns of methamphetamine use and for further interpreting the initial urinalysis; 3) patient rationales regarding the co-use of methamphetamine and opioids included strategies to mitigate the harms of heroin, as well as to detox or titrate the effects of heroin.

CONCLUSION AND IMPLICATIONS

Using an ethnographically-oriented and social science/anthropological approach and methodological complementarity to contextualize the prior urinalysis study demonstrates how behavioral variables cannot be abstracted from larger socio-structural and community contexts which impact people's decision-making process regarding co-use of methamphetamine and opioids. Further, by grounding our analysis in the meaning-centered and experiential narratives of people who use drugs, our research demonstrates the importance of considering the expertise of people who co-use opioids and methamphetamine as central for informing future sustainable program planning to address co-use that also accounts for the interrelationship between structural, community, and individual-level factors.

HIV Pre-Exposure Prophylaxis Prevention Awareness, Willingness, and Perceived Barriers among People Who Inject Drugs in Los Angeles and San Francisco, CA, 2016-2018

BACKGROUND

Pre-exposure prophylaxis (PrEP) for HIV prevention is indicated for people who inject drugs (PWID), yet most studies do not focus on PWID. This study examines factors associated with PrEP awareness and willingness, and identifies perceived barriers to PrEP among PWID. Methods: PWID were interviewed in Los Angeles and San Francisco, CA from 2016 to 2018. We analyzed data from self-reported HIV-negative participants who had injected drugs within the past 6 months (n = 469). Questions on PrEP included awareness, willingness, barriers, and uptake. Multiple logistic regression models of factors associated with awareness of, and willingness to, take PrEP were developed. Descriptive statistics on perceived PrEP barriers are reported. Results: Among HIV-negative PWID, 40% were aware of PrEP, 59% reported willingness to take PrEP, and 2% were currently taking PrEP. In multivariable analysis, PrEP awareness was associated with study site and sexual minority status, higher educational attainment, and HIV testing in the last 6 months. Willingness to take PrEP was associated with self-reported risk (paying sex partner in the last 6 months, sharing drug paraphernalia, and being injected by another PWID) and perceived HIV risk. The most common perceived barriers to PrEP were copays, concerns about increased HIV or sexually transmitted risk with PrEP, and concerns about reduction of medication efficacy without daily use. Conclusion: PrEP awareness among PWID remains inadequate. Willingness to take PrEP was moderate and was most desired by PWID who engaged in high-risk behaviors. Interventions to increase PrEP awareness and willingness, and to facilitate PrEP uptake among PWID are needed.

Opioid withdrawal symptoms, frequency, and pain characteristics as correlates of health risk among people who inject drugs

OBJECTIVE

Opioid withdrawal symptoms are widely understood to contribute to health risk but have rarely been measured in community samples of opioid using people who inject drugs (PWID).

METHODS

Using targeted sampling methods, 814 PWID who reported regular opioid use (at least 12 uses in the last 30 days) were recruited and interviewed about demographics, drug use, health risk, and withdrawal symptoms, frequency, and pain. Multivariable regression models were developed to examine factors associated with any opioid withdrawal, withdrawal frequency, pain severity, and two important health risks (receptive syringe sharing and non-fatal overdose).

RESULTS

Opioid withdrawal symptoms were reported by 85 % of participants in the last 6 months, with 29 % reporting at least monthly withdrawal symptoms and 35 % reporting at least weekly withdrawal symptoms. Very or extremely painful symptoms were reported by 57 %. In separate models, we found any opioid withdrawal (adjusted odds ratio [AOR] = 2.75, 95 % confidence interval [CI] = 1.52, 5.00) and weekly or more opioid withdrawal frequency (AOR = 1.94; 95 % CI = 1.26, 3.00) (as compared to less than monthly) to be independently associated with receptive syringe sharing while controlling for confounders. Any opioid withdrawal (AOR = 1.71; 95 % CI = 1.04, 2.81) was independently associated with nonfatal overdose while controlling for confounders. In a separate model, weekly or more withdrawal frequency (AOR = 1.69; 95 % CI = 1.12, 2.55) and extreme or very painful withdrawal symptoms (AOR = 1.53; 95 % CI = 1.08, 2.16) were associated with nonfatal overdose as well.

CONCLUSIONS

Withdrawal symptoms among PWID increase health risk. Treatment of withdrawal symptoms is urgently needed and should include buprenorphine dispensing.

Reasons for assisting with injection initiation: Results from a large survey of people who inject drugs in Los Angeles and San Francisco, California

Injection drug initiation usually requires assistance by someone who already injects drugs. To develop interventions that prevent people from starting to inject drugs, it is imperative to understand why people who inject drugs (PWID) assist with injection initiation.

METHODS

Injection initiation history and motives for initiating others were collected from 978 PWID in Los Angeles and San Francisco, CA, from 2016-17. This article documents motivations for providing injection initiation assistance and examines demographic, economic, and health-related factors associated with these motivations using multivariable logistic regression modeling.

RESULTS

Among the 405 PWID who ever facilitated injection initiation, motivations for initiating were: injury prevention (66%), skilled at injecting others (65%), to avoid being pestered (41%), in exchange for drugs/money (45%), and for food/shelter/transportation (15%). High frequency initiation (>5 lifetime injection initiations) was associated with all motivations except for being pestered. Initiation to prevent injury was associated with being female. Initiation due to pestering was associated with recycling income and sex work. Being skilled was associated with age and HIV status, while initiation for money or drugs was associated with age, race, education, social security income, and substance use treatment. Lastly, initiation for food, shelter, or transportation was associated with age, sexual orientation and education level.

CONCLUSION

Diverse factors were associated with reported motivations for assisting someone to initiate injection for the first time. Our analysis underscores the need for prevention strategies focused on improving economic and housing conditions along with implementing drug consumption rooms to disrupt the social processes of injection initiation.

Cost-effectiveness of scaling-up HCV prevention and treatment in the United States for people who inject drugs

AIMS

To examine the cost-effectiveness of hepatitis C virus (HCV) treatment of people who inject drugs (PWID), combined with medication-assisted treatment (MAT) and syringe-service programs (SSP), to tackle the increasing HCV epidemic in the United States.

DESIGN

HCV transmission and disease progression models with cost-effectiveness analysis using a health-care perspective.

SETTING

Rural Perry County, KY (PC) and urban San Francisco, CA (SF), USA. Compared with PC, SF has a greater proportion of PWID with access to MAT or SSP. HCV treatment of PWID is negligible in both settings.

PARTICIPANTS

PWID data were collected between 1998 and 2015 from Social Networks Among Appalachian People, U Find Out, Urban Health Study and National HIV Behavioral Surveillance System studies.

INTERVENTIONS AND COMPARATOR

Three intervention scenarios modeled: baseline-existing SSP and MAT coverage with HCV screening and treatment with direct-acting antiviral for ex-injectors only as per standard of care; intervention 1-scale-up of SSP and MAT without changes to treatment; and intervention 2-scale-up as intervention 1 combined with HCV screening and treatment for current PWID.

MEASUREMENTS

Incremental cost-effectiveness ratios (ICERs) and uncertainty using cost-effectiveness acceptability curves. Benefits were measured in quality-adjusted life-years (QALYs).

FINDINGS

For both settings, intervention 2 is preferred to intervention 1 and the appropriate comparator for intervention 2 is the baseline scenario. Relative to baseline, for PC intervention 2 averts 1852 more HCV infections, increases QALYS by 3095, costs $21.6 million more and has an ICER of $6975/QALY. For SF, intervention 2 averts 36 473 more HCV infections, increases QALYs by 7893, costs $872 million more and has an ICER of $11 044/QALY. The cost-effectiveness of intervention 2 was robust to several sensitivity analysis.

CONCLUSIONS

Hepatitis C screening and treatment for people who inject drugs, combined with medication-assisted treatment and syringe-service programs, is a cost-effective strategy for reducing hepatitis C burden in the United States.

Associations between perceived illicit fentanyl use and infectious disease risks among people who inject drugs

BACKGROUND

Over the last several years, fentanyl has been introduced into the illicit drug supply in the United States. While the impact of fentanyl on overdose fatalities is clear, the increase in fentanyl use may also be affecting drug use practices with implications for infectious disease transmission. We conducted a cross-sectional survey to explore associations of perceived illicit fentanyl use with opioid use frequency, injection frequency and syringe sharing among people who inject drugs in two California cities.

METHODS

People who inject drugs (PWID) were recruited from community settings in Los Angeles and San Francisco, CA from June 2017 to September 2018. Multivariable logistic regression was used to explore adjusted associations between perceived illicit fentanyl use and high frequency opioid use, high frequency injection and syringe sharing.

RESULTS

Among the 395 study participants, the median age of participants was 44 years; 74% of participants were cisgender male; 73% reported to be homeless; 61% lived in San Francisco and 39% in Los Angeles. The prevalence of perceived illicit fentanyl use in the past six months was 50.4% (95% confidence interval (CI): 45.4%-55.3%) among PWID. Findings from our adjusted logistic regression models suggested that people reporting perceived illicit fentanyl use had a greater odds of high frequency opioid use (adjusted odds ratio (aOR) = 2.36; 95% CI: 1.43-3.91; p = 0.001), high frequency injection (aOR = 1.84; 95% CI: 1.08-3.13; p = 0.03) and receptive syringe sharing (aOR = 2.16; 95% CI: 1.06-4.36; p = 0.03), as compared to people using heroin and other street drugs but not fentanyl.

CONCLUSION

People reporting perceived illicit fentanyl use were at increased risk for injection-related infectious disease risks. Actions must be taken to reduce these risks, including improved access to syringe service programs and opioid treatment and consideration of innovative approaches, such as supervised consumption services.

Self-reported sexually-transmitted infections and criminal justice involvement among women who use drugs

Background

Women involved in the criminal justice system in the United States have high rates of sexually transmitted infections (STI). It is unknown whether criminal justice involvement is a marker for other risk behavior, such as sex exchange or drug use, or criminal justice involvement itself increases risk directly.

Methods

This study examines the relationship between STI and the frequency and duration of arrest, probation, and incarceration in a sample of women who use drugs (n = 394) in Oakland, California who reported having been tested for STI in the past six months. Logistic regression models of STI using criminal justice measures as independent variables were used, and subsequent estimates were adjusted for demographics, sex exchange, specific drugs used, and number of sexual partners.

Results

Any time spent in jail in the past year was associated with higher odds of recent STI (UOR = 2.28, 95%CI [1.41–3.51]), and short incarcerations (2–3 weeks) in jail most substantially increased the odds of an STI diagnosis (UOR = 7.65, 95%CI [1.03, 56.68]). Arrest and probation were not significantly associated with STI. After adjusting for the covariates, particularly sex exchange and opioid use, none of the criminal justice-related variables were significantly associated with STI.

Conclusions

A substantial portion of the increased risk of STI that is associated with criminal justice involvement for women who use drugs is likely due to sex exchange. Longitudinal studies are needed to temporally separate criminal justice exposures, drug use, sex exchange, and STI outcomes.

•

Criminal justice involvement is common for women who use drugs.

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Short jail incarcerations (2–3 weeks) were associated with an increased odds of STI, largely accounted for by sex exchange and opioid use.

•

Qualitative studies that examine why women's sexual partnerships, opioid use, and sex exchange change after incarceration are needed.

Characteristics Associated with Nonmedical Methadone Use among People Who Inject Drugs in California

Background: Illicit, nonmedical use of opioid agonist medications such as methadone is an ongoing concern. Yet, few studies have examined nonmedical use of methadone by people who inject drugs (PWID). Objectives: This study describes the prevalence of nonmedical methadone use in a community sample of PWID and examines factors associated with recent use of nonmedical methadone. Methods: A cross-sectional sample of PWID (N = 777) was recruited using targeted sampling and interviewed in California (2011-2013). Descriptive, bivariate, and multivariate logistic regression analyses were used to determine characteristics associated with nonmedical methadone use in the last 30 days. To determine if nonmedical methadone use was associated with overdose in the last 6 months, a separate multivariate analysis was conducted. Results: Among PWID sampled, 21% reported nonmedical methadone use in the last 30 days. In multivariate logistic regression analysis, nonmedical methadone use was associated with recent methadone maintenance treatment (adjusted odds ratio [AOR] = 2.86; 95% confidence interval [CI] = 1.90, 4.30), recent nonmedical buprenorphine use (AOR = 3.12; 95% CI = 1.31, 7.47), higher injection frequency (referent <30 injections; 30-89 injections AOR = 1.89; 95% CI = 1.19, 3.02; 90-plus injections AOR = 2.43; 95% CI = 1.53, 3.87), schizophrenia diagnosis (AOR = 2.36; 95% CI = 1.36, 4.10), recent non-injection opioid prescription use (AOR = 2.97; 95% CI = 1.99, 4.43), and recent injection opioid prescription misuse (AOR = 2.13; 95% CI = 1.27, 3.59). Nonmedical methadone use was found not to be associated with nonfatal overdose (AOR = 0.77; 95% CI = 0.38, 1.56). Conclusion: Nonmedical methadone use identifies a vulnerable subpopulation among PWID, is not associated with elevated nonfatal overdose risk, and evidences a need to expand methadone treatment availability.

Scaling Up Hepatitis C Prevention and Treatment Interventions for Achieving Elimination in the United States: A Rural and Urban Comparison

In the United States, hepatitis C virus (HCV) transmission is rising among people who inject drugs (PWID). Many regions have insufficient prevention intervention coverage. Using modeling, we investigated the impact of scaling up prevention and treatment interventions on HCV transmission among PWID in Perry County, Kentucky, and San Francisco, California, where HCV seroprevalence among PWID is >50%. A greater proportion of PWID access medication-assisted treatment (MAT) or syringe service programs (SSP) in urban San Francisco (established community) than in rural Perry County (young, expanding community). We modeled the proportion of HCV-infected PWID needing HCV treatment annually to reduce HCV incidence by 90% by 2030, with and without MAT scale-up (50% coverage, both settings) and SSP scale-up (Perry County only) from 2017. With current MAT and SSP coverage during 2017-2030, HCV incidence would increase in Perry County (from 21.3 to 22.6 per 100 person-years) and decrease in San Francisco (from 12.9 to 11.9 per 100 person-years). With concurrent MAT and SSP scale-up, 5% per year of HCV-infected PWID would need HCV treatment in Perry County to achieve incidence targets-13% per year without MAT and SSP scale-up. In San Francisco, a similar proportion would need HCV treatment (10% per year) irrespective of MAT scale-up. Reaching the same impact by 2025 would require increases in treatment rates of 45%-82%. Achievable provision of HCV treatment, alongside MAT and SSP scale-up (Perry County) and MAT scale-up (San Francisco), could reduce HCV incidence.

Measures of harm reduction service provision for people who inject drugs

Coverage is an important dimension in measuring the effectiveness of needle and syringe programmes in providing sterile injecting equipment for people who inject drugs. The World Health Organization (WHO), the United Nations Office on Drugs and Crime (UNODC) and the Joint United Nations Programme on HIV/AIDS (UNAIDS) currently recommend methods for measuring coverage at the population level, that is, across an estimated population of people who inject drugs within a given geographical area. However, population-level measures of coverage rely on highly uncertain population estimates and cannot capture the different levels of syringe acquisition and injecting episodes among individual users. Consequently, such measures only broadly evaluate the extent of programme service delivery, rather than describe how people who inject drugs as individuals and sub-groups interact with needle and syringe programmes. In response to these limitations, several researchers have proposed measuring coverage at the individual level, by the percentage of injecting episodes in relation to the number of sterile needles and syringes acquired. These measures evaluate coverage according to each individual’s needs. Such measures provide enhanced information for planning and monitoring of harm reduction programmes and have now been used in multiple international research studies. We advise that WHO, UNODC and UNAIDS add individual-level coverage measurement methods to their international monitoring guidelines for harm reduction programmes. By doing this, more responsive and effective programmes can be created to better reduce injecting risk behaviours and blood-borne virus transmission among people who inject drugs.

Correlates of Sexual Coercion among People Who Inject Drugs (PWID) in Los Angeles and San Francisco, CA

Experiences of coerced or forced sex have been associated with risk for HIV infection for all adults and may be more common for gays, lesbians, bisexuals (GLB) and people who inject drugs (PWID). In this study, we explored factors associated with prior 12-month experiences of forced or coerced sex among a sample of PWID, with a focus on sexual orientation and gender. PWID (N = 772) from Los Angeles and San Francisco were recruited using targeted sampling methods in 2011-2013 and surveyed on a range of items related to demographics, drug use, HIV risk, and violence, including experiences of forced or coerced sex in the prior 12 months. In this racially/ethnically diverse, mostly homeless, and low-income sample of PWID, 25% of participants were female and 15% identified as GLB. Sexual coercion was reported by 9% of gay and bisexual men, 8% of heterosexual females, 5% of lesbians and bisexual women, and less than 1% of heterosexual men. In multivariate analyses, compared to heterosexual males, gay or bisexual males (adjusted odds ratio [AOR] = 10.68; 95% confidence interval [CI] = 2.03, 56.23), and heterosexual females (AOR = 9.69; 95% CI = 2.04, 45.94) had increased odds of coerced sex in the prior 12 months. Having a paying sex partner (AOR = 3.49; 95% CI = 1.42, 8.54) or having had forced sex prior to the age of 16 by someone at least five years older (AOR = 4.74; 95% CI = 1.88, 11.93) also elevated the odds of coercive sex. Sexual coercion is common among PWID, but especially for gay and bisexual men and heterosexual females. Efforts to reduce sexual violence among PWID are urgently needed.

Implementing Targeted Sampling: Lessons Learned from Recruiting Female Sex Workers in Baltimore, MD

Globally, HIV prevention interventions have proven efficacious among street-based female sex workers (FSWs); yet, there is a dearth of US-based HIV prevention research among this group. The lack of research among FSWs in the USA is partially driven by challenges in recruiting members of this population. The purpose of this research is to describe how targeted sampling was employed to recruit a cohort of street-based FSWs for a study that examined the role of police in shaping the HIV risk environments of street-based FSWs in Baltimore, MD. Our research demonstrates that targeted sampling can be an advantageous strategy for recruiting hidden populations that are mobile and geographically dispersed.

Depression, injecting drug use, and risky sexual behavior syndemic among women who inject drugs in Kenya: a cross-sectional survey

BACKGROUND

Injecting drug use (IDU) is a key driver of the HIV epidemic particularly when individuals experience psychosocial conditions and risky sexual behavior in a syndemic manner. This study sets out to assess evidence of a syndemic pattern of psychosocial conditions (IDU, depression, intimate partner violence (IPV)) on one the hand and risky sexual behavior on the other while accounting for the socio-economic disadvantage among women who inject drugs (WWID) in low-income urban settings in Kenya.

METHODS

Using a cross-sectional study design, this study recruited 306 WWIDs from two sites in Nairobi between January 2017 and July 2017. Multiple methodologies including descriptive analyses of co-occurrences of psychosocial conditions at the individual level, standard logistic regression analyses to examine relationships and interactions within and between psychosocial conditions and risky sexual behavior, and classification trees algorithm for predictive modeling via machine learning were employed.

RESULTS

The prevalence of the psychosocial conditions was as follows: IDU, 88%; depression, 77.1%; and IPV, 84%. The prevalence of risky sexual behavior was 69.3%. IDU and depression were related to each other (P < 0.05) and each of them with risky sexual behavior (P < 0.05). The highest 2-way and 3-way co-occurrence of conditions were reported in IDU and depression (72%) and in IDU, depression, and risky sexual behavior (62%), respectively, indicating clustering of the conditions at the individual level. Further, each additional psychosocial condition (IDU and depression) was associated with sixfold odds (P = 0.000) of having risky sexual behavior suggesting a dose-response relationship. Logistic regression analyses incorporating multiplicative interactive effects returned three significant variables (P < 0.05): IDU*depression interaction effect, "Age when delivered the first child," and "Income." Classification tree modeling represented a 5-level interaction analysis with IDU and depression predicted to have the highest influence on risky sexual behavior.

CONCLUSION

Findings provide possible evidence of a syndemic pattern involving IDU, depression, and risky sexual behavior suggesting the need for an integrated approach to the implementation of harm reduction interventions among WWID in low-income urban settings in Kenya. This work highlights the need for further studies to authenticate the findings and to characterize pathways in the syndemic development in WWID.

Factors Associated with Frequency of Recent Initiation of Others into Injection Drug Use Among People Who Inject Drugs in Los Angeles and San Francisco, CA, USA, 2016-17

Objective: Drug injection initiation is often assisted by a person who injects drugs (PWID). How often PWID provide this assistance has not been examined. We examine frequency of injection initiation assistance and factors associated with high (4+) and low frequency (1-3) initiation assistance as compared to no initiation assistance among PWID. Methods: Participants were 979 Californian PWID. PWID were interviewed about providing injection initiation assistance in the last 6 months among other items. Multinomial regression analysis was used to examine factors associated with levels of frequency of injection initiation assistance. Results: Among participants, 132 (14%) had initiated 784 people into injection (mean = 5.94 [standard deviation = 20.13]; median = 2, interquartile range = 1,4) in the last 6 months. PWID engaged in high frequency initiation (26% of sample) assisted 662 new initiates (84% of total). Using multinomial regression analysis with no initiating as the referent group, we found that high frequency initiating was statistically associated with higher injection frequency, having a paying sex partner, taking someone to a shooting gallery, and providing injection assistance. Lower frequency initiation was statistically associated with having a paying sex partner, illegal income source, and providing injection assistance. Conclusion: Differences between high and low frequency initiators were not found. Sex work and assisting with drug injection were linked to initiating others. Individual-level interventions that reduce this behavior among PWID and structural interventions such as safe consumption sites and opioid medication treatments that interrupt the social process of injection initiation should be considered as ways to reduce injection initiations.

"Starfish Sampling": a Novel, Hybrid Approach to Recruiting Hidden Populations

We sought to leverage the strengths of time location sampling (TLS) and respondent-driven sampling (RDS) for surveys of hidden populations by combing elements of both methods in a new approach we call "starfish sampling." Starfish sampling entails random selection of venue-day-time units from a mapping of the locations where the population can be found, combined with short chains of peer referrals from their social networks at the venue or presenting to the study site later. Using the population of transmen in San Francisco as a case example, we recruited 122 eligible participants using starfish sampling: 79 at randomly selected venues, 11 on dating applications, and 32 by referral. Starfish sampling produced one of the largest community-recruited samples specifically for transmen to date. Starfish sampling is a flexibility method to recruit and sample hidden populations for whom conventional TLS and RDS may not work in theory or practice.

Population-based assessment of health, healthcare utilisation, and specific needs of Syrian migrants in Germany: what is the best sampling method?

Background

Studies elucidating health-related information and special needs of Syrian migrants living in Germany are urgently required. However, data is scarce and finding appropriate sampling strategies to obtain representative results is challenging. In order to increase survey response in hard-to-reach populations, new methods were developed. One of them is respondent-driven sampling (RDS), a network sampling technique. We aimed to assess if respondent-driven sampling is a better approach to recruit Syrian migrants for health research than classical random sampling via the population registry.

Methods

A cross-sectional study was conducted in Munich between April and June 2017 inviting adults (18+ years) born in Syria to answer an online questionnaire asking for sociodemographic and health-related information. Recruitment of participants was done using a) random sampling via the population registry (PR) and b) RDS. The two study populations recruited via respondent-driven sampling and the population registry were compared to a sample drawn from the population registry with respect to gender and citizenship. In addition, the two study populations were compared to each other regarding self-reported health status, healthcare utilisation, lifestyle factors, social network size, and acculturation.

Results

Of 374 persons randomly drawn from the population registry, 49 individuals answered the questionnaire completely (response: 13.1%) while via RDS 195 participants were recruited by 16 seeds. More persons possessed German citizenship in the total sample (20.5, 95% CI: 16.6 to 24.8%) and in the PR study population (28.6, 95% CI: 16.6 to 43.3%) than in the study population (0.5, 95% CI: 0.1 to 1.5%). Participants recruited via the population registry were older, smoked less, reported more often to hold a university degree, and indicated a higher prevalence of chronic diseases, more frequent healthcare utilisation, higher scores of acculturation as well as a larger social network compared to the study population obtained via RDS.

Conclusions

Response was very low in the PR sample. The number of participants recruited via RDS was larger and led to a study population with substantially different characteristics. Our study thus indicates that RDS is a useful way to gain access to specific subgroups that are hard to reach via traditional random sampling.

Electronic supplementary material

The online version of this article (10.1186/s12874-018-0652-1) contains supplementary material, which is available to authorized users.

Peer-to-peer injection: Demographic, drug use, and injection-related risk factors

BACKGROUND

Peer-to-peer injection (either providing or receiving an injection to/from a person who injects drugs [PWID]) is common (19%-50%) among PWID. Most studies of peer-to-peer injection have focused on receiving injection assistance, with fewer examining providing injection assistance and none considering characteristics of PWID who do both. We examined characteristics of PWID by peer-to-peer injection categories (receiving, providing, both, and neither) and determined if these behaviors were associated with receptive and distributive syringe sharing.

METHODS

Los Angeles and San Francisco PWID (N = 777) were recruited using targeted sampling methods and interviewed during 2011-2013. Multinomial logistic regression was used to determine characteristics associated with peer-to-peer injection categories and logistic regression was used to examine if peer-to-peer categories were independently associated with distributive and receptive syringe sharing.

RESULTS

Recent peer-to-peer injection was reported by 42% of PWID (18% provider; 14% recipient; 10% both). In multinomial regression analysis, PWID reporting any peer-to-peer injection were more likely to inject with others than those who did neither. Injection providers and those who did both were associated with more frequent injection, illegal income source, and methamphetamine injection while injection recipients were associated with fewer years of injection. Injection providers were younger, had more years of injecting, and were more likely to inject heroin than PWID who did neither. In multivariate analyses, we found that providers and PWID who did both were significantly more likely to report receptive and distributive syringe sharing than PWID who did neither.

CONCLUSION

Peer-to-peer injection is associated with HIV/HCV risk. Current prevention strategies may not sufficiently address these behaviors. Modification of existing interventions and development of new interventions to better respond to peer-to-peer injection is urgently needed.

Dynamics study on the role of curcumin on TGF-β1 expression and pathological changes in acute paraquat poisoned rats

Role of curcumin on TGF-β1 expression and pathological changes in acute paraquat (PQ) poisoned rats were investigated. Forty-eight SD rats were divided into three groups: control group, PQ group, and PQ + curcumin group, with 16 rats in each group. PQ group rats received the lavagation of PQ every day, PQ + curcumin group was given the lavagation of curcumin treatment on the basis of the PQ group. Control group received the lavagation of physiological saline. The body weight of rats was recorded every day. Six rats were randomly selected on the 1st, 3rd and 7th day after treatment from each group and sacrificed by cervical dislocation. The blood and liver tissues of each rat were collected. The morphology change of the liver tissue was observed by hematoxylin and eosin (H&E) staining. The expression level of TGF-β1 in the liver tissue was detected by western blot analysis and RT-qPCR. The blood samples were sent to the inspection section of the hospital for the detection of reactive oxygen species (ROS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA) and superoxide dismutase (SOD). On the 1st day after poisoning, the liver cells of PQ rats had obvious edema; obvious fatty degeneration was observed on the 3rd day; and large number of cavities appeared on the 7th day due to necrosis. For the PQ + curcumin group, liver cell edema appeared on the 3rd day, and mild swelling of liver cells was observed on the 7th day. Compared with the control group, the expression of TGF-β1 was increased in the PQ group. The TGF-β1 level in PQ + curcumin group rats reached the peak on the 3rd day, then decreased, and it was lower than those in PQ group. The level of ROS, ALT, AST, MDA of the rats in PQ + curcumin group reached the highest value on the 3rd day, while the level of SOD reached the lowest value; furthermore, the level of ROS, ALT, AST, MDA was lower than that in PQ group, while the level of SOD was higher than that of the PQ group. The results showed that curcumin can effectively inhibit the expression of TGF-β1, prevent PQ-induced liver cell oxidative damage and play an important role in the protection of liver function.

Exploring Lifetime Accumulation of Criminal Justice Involvement and Associated Health and Social Outcomes in a Community-Based Sample of Women who Use Drugs

Among people who use illegal drugs, engagement with the criminal justice (CJ) system often involves an ongoing, intermittent series of arrests, incarcerations, and periods of community supervision. The potential associations between the lifetime accumulation of CJ involvement and social and health outcomes is largely unexplored. In a cross-sectional sample of women who use crack, heroin, and/ or methamphetamine recruited from communities in Oakland, CA (N = 624), we developed an approach to characterize CJ accumulation. We used latent class analysis (LCA), a multivariate person-centered method that assumes an unobserved categorical variable that divides a population into a small number of mutually exclusive and exhaustive classes. Using observed measures of incarceration and community supervision as indicator variables, we developed a model of CJ accumulation that elucidates patterns of involvement as lived by the women in the sample. Based on model fit statistics, we selected a three-class model and labeled the classes "low," "medium," and "high." We then explored associations between the classes of CJ accumulation and health and health-related outcomes using logistic regression. The odds of homelessness (p for trend = 0.004), transience (p for trend = 0.017), and recent victimization (p for trend = 0.023) were higher among women in higher accumulation classes. Higher class of CJ accumulation was associated with higher odds of reporting unmet need for physical health care (p for trend < 0.001) and mental health care (p for trend = 0.002). The odds of physical health conditions, such as hepatitis C infection (p for trend < 0.001) and mental health conditions, such as depression (p for trend = 0.003), also increased with higher class of accumulation. While the findings described here are limited by the cross-sectional nature of the study, they suggest that CJ accumulation is a potentially meaningful concept for assessing associations between the CJ system and health-related issues.

Accumulation of Jail Incarceration and Hardship, Health Status, and Unmet Health Care Need Among Women Who Use Drugs

BACKGROUND

Jail is frequently described as a "revolving door," which can be profoundly destabilizing to people moving in and out of the system. However, there is a dearth of research attempting to understand the impacts of the accumulation of incarceration events on women who use drugs. We examined the association of the frequency of jail incarceration with hardship, perceived health status, and unmet health care need among women who use drugs.

METHODS

Our community-based sample included women who use heroin, methamphetamine, crack cocaine, and/or powder cocaine (N = 624) in Oakland, California, from 2012 to 2014. Poisson regression models with robust variances were built to estimate adjusted prevalence ratios between the frequency of jail incarcerations and measures of hardship, perceived health, and unmet health care need, adjusting for a set of a priori specified covariates.

RESULTS

We observed associations between high levels of jail frequency and higher levels of homelessness (p = .024), feeling unsafe in their living situation (p = .011), stress (p = .047), fair to poor mental health (p = .034), unmet mental health care need (p = .037), and unmet physical health care need (p = .041). We did not observe an association between jail frequency and unmet subsistence needs score or fair to poor physical health.

CONCLUSIONS

We observed associations between higher levels of jail frequency and a higher prevalence of hardship, poor mental health, and unmet health care need. Our findings suggest areas for additional research to untangle the impacts of frequent incarceration on women's health and well-being.

Opioid misuse initiation: Implications for intervention

The nonmedical use of opioids (e.g., prescription painkillers and heroin) has drastically increased over the past two decades. Despite the popular media narrative suggesting initiation often begins with misused personal prescriptions, there has been surprisingly little investigation into how persons initiate their misuse of opioids. Inattention to initiation patterns is an important limitation because understandings of onset directly inform prevention and treatment interventions. The primary goals of this study, therefore, were to: (1) describe the age patterns of opioid misuse initiation, (2) identify the opioid most commonly used at initiation and the source of the initial opioids, and (3) explore the narrative accounts of the circumstances surrounding opioid misuse onset. Surveys (n = 125) and in-depth interviews (n = 30) were conducted with nonmedical opioid users currently residing in southwest Pennsylvania between July 2017 and July 2018. Survey results show that initiation of opioid misuse (both heroin and prescription opioids) tends to occur prior to age 25, peaking between the ages of 18-25, with most (81%) initiating with prescription opioids. Qualitative findings provided additional context regarding the timing of initiation, acquiring opioids at initiation, and motivations for initiating. This study adds to the limited research on opioid misuse initiation and provides insights to drug treatment providers, prescribers, and public health professionals in identifying who is at risk for opioid misuse initiation, and more importantly, when and how to intervene most effectively.

Overlooked Threats to Respondent Driven Sampling Estimators: Peer Recruitment Reality, Degree Measures, and Random Selection Assumption

Intensive sociometric network data were collected from a typical respondent driven sample (RDS) of 528 people who inject drugs residing in Hartford, Connecticut in 2012-2013. This rich dataset enabled us to analyze a large number of unobserved network nodes and ties for the purpose of assessing common assumptions underlying RDS estimators. Results show that several assumptions central to RDS estimators, such as random selection, enrollment probability proportional to degree, and recruitment occurring over recruiter's network ties, were violated. These problems stem from an overly simplistic conceptualization of peer recruitment processes and dynamics. We found nearly half of participants were recruited via coupon redistribution on the street. Non-uniform patterns occurred in multiple recruitment stages related to both recruiter behavior (choosing and reaching alters, passing coupons, etc.) and recruit behavior (accepting/rejecting coupons, failing to enter study, passing coupons to others). Some factors associated with these patterns were also associated with HIV risk.

Differences in time to injection onset by drug in California: Implications for the emerging heroin epidemic

BACKGROUND

Heroin use is increasing in the US. Heroin use may predispose users towards injection routes of drug administration as compared to other illicit substances.

OBJECTIVE

To explore the relationship between heroin use and drug injection, we compared time from first use to first injection (referred to as time to injection onset by drug [TTIOD]) of heroin, methamphetamine/speed, cocaine, and crack cocaine among people who inject drugs (PWID).

METHODS

Age of first use and first injection by drug was collected from 776 PWID. Survival analyses were used to determine TTIOD and to examine demographic factors associated with TTIOD. Cox regression analysis was used to determine demographic factors associated with drug-specific injection onset.

RESULTS

The eventual injection onset rate by the drug was 99% for participants who used heroin, 85% for participants who used methamphetamine/speed, 80% for participants who used powder cocaine, and 38% for participants who used crack cocaine. Hazard ratios for injection use within one year of first use by drug were: 1.37 (median survival time [MST] = 0.61 years) for heroin, 0.66 (MST = 1.10 years) for methamphetamine/speed, 0.50 (MST = 2.93 years) for powder cocaine, and 0.12 (MST = 39.59 years) for crack cocaine. Demographic differences in TTIOD were found for each drug. Demographic differences were found for eventual injection by drug for all substances except heroin.

CONCLUSION

Among PWID, heroin use was associated with a more rapid transition to injection and a higher rate of eventual heroin injection regardless of demographics. More robust, innovative efforts to reduce heroin use and prevent injection initiation are urgently needed.

Measures of human immunodeficiency virus (HIV) community viral load and HIV incidence among people who inject drugs

PURPOSE

To evaluate the measures of community human immunodeficiency virus (HIV) viral load (VL) and the association with HIV incidence among people who inject drugs (PWID).

METHODS

Data were from 1986 to 1999 Urban Health Study conducted among PWID in the San Francisco Bay Area. Extant measures of community VL use mean VL among HIV + study participants, not accounting for the proportion of HIV- individuals. We compared the strength of the associations between HIV incidence and the traditionally measured mean community VL and a new prevalence-adjusted community VL, calculated by dividing the sum of VL among HIV + participants by the total participants irrespective of HIV status.

RESULTS

Mean community VL was not correlated with HIV incidence in this sample of PWID (rs = 0.32, P = .28). However, prevalence-adjusted community VL was strongly correlated with HIV incidence (rs = 0.69, P = .009). Nested complimentary log-log linear models indicated that increases in community VL and prevalence-adjusted community VL were both associated with HIV incidence, but prevalence-adjusted community VL was a more sensitive measure (hazard ratio = 1.28, P = .038 and hazard ratio = 3.29, P < .001, respectively).

CONCLUSIONS

The effect of community VL on HIV incidence may be stronger than previously reported. Future studies of community VL surveillance should consider accounting for the prevalence of HIV using a prevalence-adjusted community VL measure.

A Strengths-Based Case Management Intervention to Reduce HIV Viral Load Among People Who Use Drugs

Engaging highly marginalized HIV positive people in sustained medical care is vital for optimized health and prevention efforts. Prior studies have found that strengths-based case management helps link people who use drugs to HIV care. We conducted a pilot to assess whether a strengths-based case management intervention may help people who use injection drugs (PWID) or smoke crack cocaine (PWSC) achieve undetectable HIV viral load. PWID and PWSC were recruited in Oakland, California using targeted sampling methods and referral from jails and were tested for HIV. HIV positive participants not receiving HIV care (n = 19) were enrolled in a pilot strengths-based case management intervention and HIV positive participants already in HIV care (n = 29) were followed as comparison participants. The intervention was conducted by a social worker and an HIV physician. Special attention was given to coordinating care as participants cycled through jail and community settings. Surveys and HIV viral load tests were conducted quarterly for up to 11 visits. HIV viral load became undetectable for significantly more participants in the intervention than in the comparison group by their last follow-up (intervention participants: 32% at baseline and 74% at last follow-up; comparison participants: 45% at baseline and 34% at last follow-up; p = 0.008). In repeated measures analysis, PBO intervention participants had higher odds of achieving undetectable viral load over time than comparison participants (p = 0.033). Strengths-based case management may help this highly vulnerable group achieve undetectable HIV viral load over time.

Patterns of Twitter Behavior Among Networks of Cannabis Dispensaries in California

Background

Twitter represents a social media platform through which medical cannabis dispensaries can rapidly promote and advertise a multitude of retail products. Yet, to date, no studies have systematically evaluated Twitter behavior among dispensaries and how these behaviors influence the formation of social networks.

Objectives

This study sought to characterize common cyberbehaviors and shared follower networks among dispensaries operating in two large cannabis markets in California.

Methods

From a targeted sample of 119 dispensaries in the San Francisco Bay Area and Greater Los Angeles, we collected metadata from the dispensary accounts using the Twitter API. For each city, we characterized the network structure of dispensaries based upon shared followers, then empirically derived communities with the Louvain modularity algorithm. Principal components factor analysis was employed to reduce 12 Twitter measures into a more parsimonious set of cyberbehavioral dimensions. Finally, quadratic discriminant analysis was implemented to verify the ability of the extracted dimensions to classify dispensaries into their derived communities.

Results

The modularity algorithm yielded three communities in each city with distinct network structures. The principal components factor analysis reduced the 12 cyberbehaviors into five dimensions that encompassed account age, posting frequency, referencing, hyperlinks, and user engagement among the dispensary accounts. In the quadratic discriminant analysis, the dimensions correctly classified 75% (46/61) of the communities in the San Francisco Bay Area and 71% (41/58) in Greater Los Angeles.

Conclusions

The most centralized and strongly connected dispensaries in both cities had newer accounts, higher daily activity, more frequent user engagement, and increased usage of embedded media, keywords, and hyperlinks. Measures derived from both network structure and cyberbehavioral dimensions can serve as key contextual indicators for the online surveillance of cannabis dispensaries and consumer markets over time.

Associations of criminal justice and substance use treatment involvement with HIV/HCV testing and the HIV treatment cascade among people who use drugs in Oakland, California

Background

People who smoke crack cocaine and people who inject drugs are at-risk for criminal justice involvement as well as HIV and HCV infection. Compared to criminal justice involvement, substance use treatment (SUT) can be cost-effective in reducing drug use and its associated health and social costs. We conducted a cross-sectional study of people who smoke crack cocaine and people who inject drugs to examine the association between incarceration, community supervision and substance use treatment with HIV/HCV testing, components of the HIV treatment cascade, social and physical vulnerability and risk behavior.

Methods

Targeted sampling methods were used to recruit people who smoke crack cocaine and people who inject drugs (N = 2072) in Oakland, California from 2011 to 2013. Poisson regression models were used to estimate adjusted prevalence ratios between study exposures and outcomes.

Results

The overall HIV prevalence was 3.3% (95% CI 2.6–4.1). People previously experiencing incarceration were 21% (p < 0.001) and 32% (p = 0.001), respectively, more likely to report HIV and HCV testing; and were not more likely to report receiving HIV care or initiating ART. People previously experiencing community supervision were 17% (p = 0.001) and 15% (p = 0.009), respectively, more likely to report HIV and HCV testing; and were not more likely to report receiving HIV care or initiating ART. People with a history of SUT were 15% (p < 0.001) and 23% (p < 0.001), respectively, more likely to report receiving HIV and HCV testing, 67% (p = 0.016) more likely to report HIV care, and 92% (p = 0.012) more likely to report HIV treatment initiation. People previously experiencing incarceration or community supervision were also more likely to report homelessness, trouble meeting basic needs and risk behavior.

Conclusions

People with a history of substance use treatment reported higher levels of HCV and HIV testing and greater access to HIV care and treatment among HIV-positive individuals. People with a history of incarceration or community supervision reported higher levels of HCV and HIV testing, but not greater access to HIV care or treatment among HIV-positive individuals., Substance use treatment programs that are integrated with other services for HIV and HCV will be critical to simultaneously address the underlying reasons drug-involved people engage in drug-related offenses and improve access to essential medical services.

Utilizing Big Data and Twitter to Discover Emergent Online Communities of Cannabis Users

Large shifts in medical, recreational, and illicit cannabis consumption in the United States have implications for personalizing treatment and prevention programs to a wide variety of populations. As such, considerable research has investigated clinical presentations of cannabis users in clinical and population-based samples. Studies leveraging big data, social media, and social network analysis have emerged as a promising mechanism to generate timely insights that can inform treatment and prevention research. This study extends a novel method called stochastic block modeling to derive communities of cannabis consumers as part of a complex social network on Twitter. A set of examples illustrate how this method can ascertain candidate samples of medical, recreational, and illicit cannabis users. Implications for research planning, intervention design, and public health surveillance are discussed.