Understanding intentionality of fentanyl use and drug overdose risk: Findings from a mixed methods study of people who inject drugs in New York City

Endogenous opiates and behavior: 2023

This paper is the forty-sixth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2023 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug and alcohol abuse (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Heroin or fentanyl: Prevalence of confirmed fentanyl in ED patients with suspected heroin overdose

Background

United States drug overdose deaths are being driven by the increasing prevalence of fentanyl, but whether patients are knowingly using fentanyl is unclear. We examined the analytical confirmation of fentanyl in emergency department (ED) patients with documented heroin overdose.

Hypothesis

We hypothesized that the proportion of fentanyl and fentanyl analogs would be higher than that of confirmed heroin.

Methods

This is a subgroup analysis from a prospective multicenter consecutive cohort of ED patients age 18+ with opioid overdose presenting to 10 US sites within the Toxicology Investigators Consortium from 2020 to 2021. Toxicology analysis was performed using liquid chromatography quadrupole time-of-flight mass spectrometry. De-identified toxicology results were paired with the clinical database. The primary outcome was the proportion of patients with fentanyl analytes detected in their serum.

Results

Of 1006 patients screened, 406 were eligible, and of 168 patients who reported that they had taken heroin or had a documented heroin overdose, 88% (n = 147) were in fact found to have fentanyl and/or a fentanyl analog present on serum analysis (p < 0.0001). In contrast, only 46 of the 168 patients with reported or documented heroin overdose (27%) were found to have heroin biomarkers present.

Conclusion

The prevalence of confirmed fentanyl in ED patients with suspected heroin overdose was extremely high, while the prevalence of heroin was very low. There was a high degree of mismatch between the opioids believed to be the overdose agent versus the actual opioids identified on serum toxicology. Clinicians in the United States should presume that fentanyl is involved in all illicit opioid overdoses and should counsel patients on harm reduction measures.

Implementation of Medications for Alcohol and Opioid Use Disorders in a Value-Based Organization-Unlocking Value by Addressing Unmet Needs for Medicaid and Dually-Eligible Beneficiaries

The authors describe a rapid implementation of medication treatment for substance use disorders in a value-based organization, delivered in the community-based, interdisciplinary primary care of Medicaid and dual-eligible members. The determinants of increased need are reviewed, as well as the growing opportunity to improve access to treatments, and a template for implementation is shared.

Harm Reduction and Treatment Among People at High Risk of Overdose

Importance

Rates of overdose deaths involving synthetic opioids remain high, increasingly involve stimulants combined with opioids, and are increasing rapidly in racially and ethnically minoritized communities, yet little is known about access to harm reduction and treatment services in these groups.

Objective

To characterize access and barriers to harm reduction and treatment in a racially and ethnically diverse population of people who use drugs.

Design, Setting, and Participants

A cross-sectional telephone survey of people recruited from 39 treatment, harm reduction, and social service organizations in Milwaukee County, Wisconsin; Flint and Detroit, Michigan; and statewide in New Jersey was conducted from January 30 to July 28, 2023. Adults who used cocaine, methamphetamine, or opioids in the past 30 days called a study hotline and completed an interview in English or Spanish.

Exposures

Overdose experience, drug types used (opioids only, stimulants only, and polysubstance), and social risk factors (eg, financial instability and criminal legal involvement).

Main Outcomes and Measures

Recent use of any harm reduction services, fentanyl test strips, naloxone possession, treatment, and self-reported barriers to services.

Results

Of the total sample of 1240 adults, 486 (39.2%) were Black non-Hispanic, 183 (14.8%) were Hispanic, and 464 (37.4%) were White non-Hispanic. In the past 30 days, 826 individuals (66.6%) were polysubstance users, 135 (10.9%) used only opioids, and 279 (22.5%) used only stimulants. A total of 349 respondents (28.1%) experienced a prior-year overdose. Compared with those without a prior-year overdose, people with overdose were more likely to possess naloxone (80.7% vs 68.2%; P < .001), possess fentanyl test strips (36.8% vs 23.5%; P < .001), and use harm reduction services (63.4% vs 53.0%; P = .003), while differences in treatment use were nonsignificant (52.0% vs 46.6%; P = .24). Among stimulant-only users, 51.4% possessed naloxone compared with 77.3% of opioid-only users (P < .001) and 77.6% of polysubstance users (P < .001), with similar disparities in fentanyl test strip possession.

Conclusions and Relevance

In this cross-sectional study of people who used drugs in the past 30 days, findings highlighted low use of harm reduction and treatment services among people who use stimulants. Additional communication regarding their importance may help increase the use of the services amidst a rapidly changing drug supply.

Barriers to, and Facilitators of, Checking Drugs for Adulterants in the Era of Fentanyl and Xylazine: Qualitative Study

BACKGROUND

Overdose deaths continue to reach new records in New York City and nationwide, largely driven by adulterants such as fentanyl and xylazine in the illicit drug supply. Unknowingly consuming adulterated substances dramatically increases risks of overdose and other health problems, especially when individuals consume multiple adulterants and are exposed to a combination of drugs they did not intend to take. Although test strips and more sophisticated devices enable people to check drugs for adulterants including fentanyl and xylazine prior to consumption and are often available free of charge, many people who use drugs decline to use them.

OBJECTIVE

We sought to better understand why people in the New York City area do or do not check drugs before use. We plan to use study findings to inform the development of technology-based interventions to encourage consistent drug checking.

METHODS

In summer 2023, team members who have experience working with people who use drugs conducted 22 semistructured qualitative interviews with a convenience sample of people who reported illicit drug use within the past 90 days. An interview guide examined participants' knowledge of and experience with adulterants including fentanyl, xylazine, and benzodiazepines; using drug testing strips; and whether they had ever received harm reduction services. All interviews were audio recorded, transcribed, and analyzed for emerging themes.

RESULTS

Most participants lacked knowledge of adulterants, and only a few reported regularly checking drugs. Reasons for not checking included lacking convenient access to test supplies, or a place to check samples out of the public's view, as well as time considerations. Some participants also reported a strong belief that they were not at risk from fentanyl, xylazine, or other adulterants because they exclusively used cocaine or crack, or that they were confident the people they bought drugs from would not sell them adulterated substances. Those who did report testing their drugs described positive interactions with harm reduction agency staff.

CONCLUSIONS

New forms of outreach are needed not only to increase people's knowledge of adulterated substances and awareness of the increasing risks they pose but also to encourage people who use drugs to regularly check their substances prior to use. This includes new intervention messages that highlight the importance of drug checking in the context of a rapidly changing and volatile drug supply. This messaging can potentially help normalize drug checking as an easily enacted behavior that benefits public health. To increase effectiveness, messages can be developed with, and outreach can be conducted by, trusted community members including people who use drugs and, potentially, people who sell drugs. Pairing this messaging with access to no-cost drug-checking supplies and equipment may help address the ongoing spiral of increased overdose deaths nationwide.

Opioid use, prescribing and fatal overdose patterns among racial/ethnic minorities in the United States: A scoping review and conceptual risk environment model

ISSUES

To date, there has been no synthesis of research addressing the scale and nuances of the opioid epidemic in racial/ethnic minority populations in the United States that considers the independent and joint impacts of dynamics such as structural disadvantage, provider bias, health literacy, cultural norms and various other risk factors.

APPROACH

Using the "risk environment" framework, we conducted a scoping review on PubMed, Embase and Google Scholar of peer-reviewed literature and governmental reports published between January 2000 and February 2024 on the nature and scale of opioid use, opioid prescribing patterns, and fatal overdoses among racial/ethnic minorities in the United States, while also examining macro, meso and individual-level risk factors.

KEY FINDINGS

Results from this review illuminate a growing, but fragmented, literature lacking standardisation in racial/ethnic classification and case reporting, specifically in regards to Indigenous and Asian subpopulations. This literature broadly illustrates racial/ethnic minorities' increasing nonmedical use of opioids, heightened burdens of fatal overdoses, specifically in relation to polydrug use and synthetic opioids, with notable elevations among Black/Latino subgroups, in addition uneven opioid prescribing patterns. Moreover, the literature implicates a variety of unique risk environments corresponding to dynamics such as residential segregation, provider bias, overpolicing, acculturative stress, patient distrust, and limited access to mental health care services and drug treatment resources, including medications for opioid use disorder.

IMPLICATIONS

There has been a lack of rigorous, targeted study on racial/ethnic minorities who use opioids, but evidence highlights burgeoning increases in usage, especially polydrug/synthetic opioid use, and disparities in prescriptions and fatal overdose risk-phenomena tied to multi-level forms of entrenched disenfranchisement.

CONCLUSION

There is a need for further research on the complex, overlapping risk environments of racial/ethnic minorities who use opioids, including deeper inclusion of Indigenous and Asian individuals, and efforts to generate greater methodological synergies in population classification and reporting guidelines.

COVID-19 vaccination uptake and determinants of booster vaccination among persons who inject drugs in New York City

BACKGROUND

Persons who inject drugs (PWID) may be unengaged with healthcare services and face an elevated risk of severe morbidity and mortality associated with COVID-19 due to chronic diseases and structural inequities. However, data on COVID-19 vaccine uptake, particularly booster vaccination, among PWID are limited. We examined COVID-19 vaccine uptake and factors associated with booster vaccination among PWID in New York City (NYC).

METHODS

We recruited PWID using respondent-driven sampling from October 2021 to November 2023 in a survey that included HIV and SARS-CoV-2 antibodies testing. The questionnaire included demographics, COVID-19 vaccination and attitudes, and drug use behaviors.

RESULTS

Of 436 PWID, 80% received at least one COVID-19 vaccine dose. Among individuals who received at least one COVID-19 vaccine dose, 95% were fully vaccinated. After excluding participants recruited before booster authorization for general adults started in NYC, and those who had never received an initial vaccination, 41% reported having received a COVID-19 booster vaccine dose. COVID-19 booster vaccination was significantly associated with having a high school diploma or GED (adjusted odds ratio (aOR) 1.93; 95% confidence interval (CI) 1.09, 3.48), ever received the hepatitis A/B vaccine (aOR 2.23; 95% CI 1.27, 3.96), main drug use other than heroin/speedball, fentanyl and stimulants (aOR 14.4; 95% CI 2.32, 280), number of non-fatal overdoses (aOR 0.35; 95% CI 0.16, 0.70), and mean vaccination attitude score (aOR 0.94; 95% CI 0.89, 0.98).

CONCLUSIONS

We found a suboptimal level of COVID-19 booster vaccination among PWID, which was consistent with the rates observed in the general population in NYC and the U.S. Community-based interventions are needed to improve COVID-19 booster vaccination access and uptake among PWID. Attitudes towards vaccination were significant predictors of both primary and booster vaccination uptake. Outreach efforts focusing on improving attitudes towards vaccination and educational programs are essential for reducing hesitancy and increasing booster vaccination uptake among PWID.

High-dose naloxone formulations are not as essential as we thought

Naloxone is an effective FDA-approved opioid antagonist for reversing opioid overdoses. Naloxone is available to the public and can be administered through intramuscular (IM), intravenous (IV), and intranasal spray (IN) routes. Our literature review investigates the adequacy of two doses of standard IM or IN naloxone in reversing fentanyl overdoses compared to newer high-dose naloxone formulations. Moreover, our initiative incorporates the experiences of people who use drugs, enabling a more practical and contextually-grounded analysis. The evidence indicates that the vast majority of fentanyl overdoses can be successfully reversed using two standard IM or IN dosages. Exceptions include cases of carfentanil overdose, which necessitates ≥ 3 doses for reversal. Multiple studies documented the risk of precipitated withdrawal using ≥ 2 doses of naloxone, notably including the possibility of recurring overdose symptoms after resuscitation, contingent upon the half-life of the specific opioid involved. We recommend distributing multiple doses of standard IM or IN naloxone to bystanders and educating individuals on the adequacy of two doses in reversing fentanyl overdoses. Individuals should continue administration until the recipient is revived, ensuring appropriate intervals between each dose along with rescue breaths, and calling emergency medical services if the individual is unresponsive after two doses. We do not recommend high-dose naloxone formulations as a substitute for four doses of IM or IN naloxone due to the higher cost, risk of precipitated withdrawal, and limited evidence compared to standard doses. Future research must take into consideration lived and living experience, scientific evidence, conflicts of interest, and the bodily autonomy of people who use drugs.

National and regional trends in fentanyl seizures in the United States, 2017-2023

BACKGROUND

Rates of synthetic opioid-related deaths over time and across regions have been compared within the US, but other indicator data could help inform prevention and harm reduction as well. We compared regional trends in fentanyl seizures to examine potential shifts in illicit fentanyl availability.

METHODS

Annual trends in fentanyl seizures were examined using data from High Intensity Drug Trafficking Areas for the US overall and by region from 2017 through 2023. Multiple measures included the number of seizures, the number of powder seizures, the number of pill seizures, the total weight of seizures, the number of pills seized, and the percentage of the number of pill seizures relative to the number of total seizures.

RESULTS

The percentage of seizures in pill form in the US increased from 10.3 % in 2017 to 49.0 % in 2023 (adjusted annual percentage change [AAPC]=25.2, 95 % CI: 17.6, 33.2), with 115.6 million individual pills seized in 2023. Pill weight related to total seizure weight also increased from 0.4 % to 54.5 % (AAPC=112.6, 95 % CI: 78.6, 153.2). In 2023, the plurality of seizures was in the West, in seven out of eight of our measures, with 77.8 % of seizures in the West being in pill form. Although the Midwest had lower prevalence of seizures than the West, there were notable increases in the Midwest in the number of pill seizures (AAPC=142.2, 95 % CI: 91.9, 205.8) and number of pills seized (AAPC=421.0, 95 % CI: 272.7, 628.4). Total weight of fentanyl seized increased the most in the West (AAPC=84.6, 95 % CI: 72.3, 97.8).

CONCLUSIONS

The number and size of fentanyl seizures is increasing in the US, with the majority of seizures, especially in pill form, in the West. Continued monitoring of regional shifts in the fentanyl supply can help inform targeted prevention and public health response.

Association between willingness to use an overdose prevention center and probation or parole status among people who use drugs in Rhode Island

BACKGROUND

Overdose prevention centers (OPCs) are being implemented in the United States as a strategy to reduce drug-related mortality and morbidity. Previous studies have suggested that people who use drugs (PWUD) with a history of criminal legal system (CLS) involvement (e.g. current probation/parole) are at greater risk of overdose but may also encounter significant barriers to OPC use. The objective of this study was to explore the association between willingness to use an OPC and probation/parole status in a sample of PWUD in Rhode Island.

METHODS

This study utilized data from the Rhode Island Prescription and Illicit Drug Study, which enrolled adult PWUD from August 2020 to February 2023. We used Pearson's chi-square and Wilcoxon rank-sum tests to assess bivariate associations between willingness to use an OPC and probation/parole status (current/previous/never), as well as other sociodemographic and behavioral characteristics. In multivariable Poisson analyses, we examined the association between willingness to use an OPC and probation/parole status, adjusting for key sociodemographic and behavioral characteristics.

RESULTS

Among 482 study participants, 67% were male, 56% identified as white, 20% identified as Hispanic/Latine, and the median age was 43 (IQR 35-53). Nearly a quarter (24%) had never been on probation/parole, 44% were not currently on probation/parole but had a lifetime history of probation and parole, and 32% were currently on probation/parole. Most participants (71%) reported willingness to use an OPC, and in both bivariate and multivariable analyses, willingness to use an OPC did not vary by probation/parole status. Crack cocaine use and lifetime non-fatal overdose were associated with greater willingness to use an OPC (all p < 0.05).

CONCLUSIONS

These data demonstrate high willingness to use OPC among PWUD in Rhode Island regardless of CLS-involvement. As OPCs begin to be implemented in Rhode Island, it will be imperative to engage people with CLS-involvement and to ensure access to the OPC and protection against re-incarceration due to potential barriers, such as police surveillance of OPCs.

Prevalence and drug use correlates of inadvertent fentanyl exposure among individuals misusing drugs in seven U.S. states

Fentanyl has emerged as the leading cause of fatal drug overdoses in the U.S. Individuals misusing drugs may not always be aware of exposure to fentanyl.

To determine the prevalence of fentanyl use and extent of awareness of fentanyl exposure among a national sample of treatment-seeking individuals with opioid use disorder (n = 1098).

Participants provided oral fluid and urine specimens, which were tested for drugs by liquid chromatography/tandem mass spectrometry. Participants also provided self-reports of fentanyl use.

49.5% tested positive for fentanyl in oral fluid, urine, or both. Of those testing positive for fentanyl, 29.8% were unaware that they had been exposed to fentanyl. Participants testing positive for opioids methadone, and specifically 6-monoacetylmorphine (6-MAM), a unique metabolite of heroin, were significantly more likely to be unaware of fentanyl exposure than participants testing negative for these substances, with a similar trend for oxycodone and tramadol.

These findings may be due to fentanyl's effect being difficult to distinguish from that of other opioids, whereas when other types of drugs are adulterated with fentanyl, the differences in effects are likely to be readily discernable. These results support the importance of expanded drug-checking services.

Effects of inhaled low-concentration xenon gas on naltrexone-precipitated withdrawal symptoms in morphine-dependent mice

BACKGROUND

Opioid withdrawal symptoms (OWS) are highly aversive and prompt unprescribed opioid use, which increases morbidity, mortality, and, among individuals being treated for opioid use disorder (OUD), recurrence. OWS are driven by sympathetic nervous system (SNS) hyperactivity that occurs when blood opioid levels wane. We tested whether brief inhalation of xenon gas, which inhibits SNS activity and is used clinically for anesthesia and diagnostic imaging, attenuates naltrexone-precipitated withdrawal-like signs in morphine-dependent mice.

METHODS

Adult CD-1 mice were implanted with morphine sulfate-loaded (60 mg/ml) minipumps and maintained for 6 days to establish morphine dependence. On day 7, mice were given subcutaneous naltrexone (0.3 mg/kg) and placed in a sealed exposure chamber containing either 21% oxygen/balance nitrogen (controls) or 21% oxygen/added xenon peaking at 30%/balance nitrogen. After 10 minutes, mice were transferred to observation chambers and videorecorded for 45 minutes. Videos were scored in a blind manner for morphine withdrawal behaviors. Data were analyzed using 2-way ANOVAs testing for treatment and sex effects.

RESULTS AND CONCLUSIONS

Xenon-exposed mice exhibited fewer jumps (P = 0.010) and jumping suppression was detectible within the first 10-minute video segment, but no sex differences were detected. Brief inhalation of low concentration xenon rapidly and substantially attenuated naltrexone-precipitated jumping in morphine-dependent mice, suggesting that it can inhibit OWS. If xenon effects translate to humans with OUD, xenon inhalation may be effective for reducing OWS, unprescribed opioid use, and for easing OUD treatment initiation, which could help lower excess morbidity and mortality associated with OUD.

Evaluation of Low-dose Buprenorphine Initiation With Buprenorphine Buccal Films in Hospitalized Patients: A Retrospective Cohort Study

OBJECTIVE

Low-dose buprenorphine initiation (LDBI) strategies to transition patients from full opioid agonists to buprenorphine have previously been described using sublingual films, intravenous solution, transdermal patches, and, more recently, buccal films. The objective of this study was to describe the effectiveness of LDBI using novel titration schedules with buccal films.

METHODS

This is a retrospective cohort study of hospitalized patients with opioid use disorder (OUD) or physiologic dependence to opioids who underwent LDBI with buprenorphine buccal films at NYU Langone Health. Two LDBI protocols were evaluated, including a short titration schedule over 4 days and a long schedule over 7 days. The primary outcomes of interest included LDBI completion rates and incidence of opioid withdrawal.

RESULTS

Forty-two patients underwent 46 LDBIs at NYU Langone Health between October 2020 and April 2022. The cohort comprised patients with OUD (57%), chronic pain with OUD (33%), and chronic pain without OUD (10%). Indications for LDBI most commonly included co-occurring pain precluding discontinuation of full opioid agonists (72%), prior history of precipitated withdrawal (30%), and methadone use (23%). The overall completion rate of LDBI was 78%. Withdrawal was encountered in 33% of patients; however, only 2 patients required LDBI discontinuation as a result. On multivariate analysis, a diagnosis of OUD was independently associated with withdrawal during LDBI.

CONCLUSIONS

Buprenorphine buccal films can successfully be used off-label to facilitate LDBI in the hospital setting. We present 4- and 7-day titration protocols, which were well-tolerated, and provide practical considerations for use.

Factors Associated with Gaps in Naloxone Knowledge: Evidence from a 2022 Great Plains Survey

Background

The rising prevalence of fast-acting opioids in the United States suggests the increased need for non-first responder administration of naloxone. Effective administration of naloxone during an overdose requires that bystanders are familiar with, have access to, and know how to use naloxone.

Methods

Drawing on the 2022 Nebraska Annual Social Indicators survey, we analyzed naloxone familiarity, access, and competency to administer among a statewide, address-based sample of Nebraskan adults.

Results

There were significant gaps in naloxone knowledge in Nebraska. Although 75.6% of respondents were familiar with naloxone, only 18.6% knew how to access naloxone and 17.6% knew how to use naloxone. We find that more frequent religious service attendance is associated with lower odds of naloxone familiarity. Among those familiar with naloxone, a higher perception of community stigma towards opioids generally is associated with lower odds of naloxone access and competency. Higher perception of community stigma towards heroin, methamphetamines, and cocaine, however, is associated with higher odds of naloxone access. Finally, past overdose experience, lifetime illicit opioid use, being close to a person who uses opioids, and having access to illicit opioids was not significantly associated with naloxone familiarity, access, or competency among respondents in Nebraska's two largest cities, Omaha and Lincoln. Outside of these cities, past overdose experience and access to illicit opioids was associated with higher odds of naloxone access and competency, but lifetime opioid use and being close to a person who uses opioids had no effect.

Conclusions

Our findings highlight the continued need for education on naloxone with a specific focus on access and competency to further reduce opioid-related overdose deaths. Education campaigns targeted at places of worship or individuals close to people who use opioids may further serve those with a lower likelihood of naloxone familiarity and promote knowledge of naloxone among those with higher odds of encountering an overdose. Further work is needed to understand differences in the relationship between substance-specific perceived stigma and its association with naloxone access.

High-Dose Naloxone Formulations Are Not as Essential as We Thought

Naloxone is a U.S. Food and Drug Administration (FDA) approved opioid antagonist for reversing opioid overdoses. Naloxone is available to the public, and can be administered through intramuscular (IM), intravenous (IV), and intranasal spray (IN) routes. Our literature review aimed to improve understanding regarding the adequacy of the regularly distributed two doses of low-dose IM or IN naloxone in effectively reversing fentanyl overdoses and whether high-dose naloxone formulations (HDNF) formulations are an optimal solution to this problem. Moreover, our initiative incorporated the perspectives and experiences of people who use drugs (PWUD), enabling a more practical and contextually-grounded analysis. We began by discussing the knowledge and perspectives of Tennessee Harm Reduction, a small peer-led harm reduction organization. A comprehensive literature review was then conducted to gather relevant scholarly works on the subject matter. The evidence indicates that, although higher doses of naloxone have been administered in both clinical and community settings, the vast majority of fentanyl overdoses can be successfully reversed using standard IM dosages with the exception of carfentanil overdoses and other more potent fentanyl analogs, which necessitate three or more doses for effective reversal. Multiple studies documented the risk of precipitated withdrawal using high doses of naloxone. Notably, the possibility of recurring overdose symptoms after resuscitation exists, contingent upon the half-life of the specific opioid. Considering these findings and the current community practice of distributing multiple doses, we recommend providing at least four standard doses of IN or IM naloxone to each potential bystander, and training them to continue administration until the recipient achieves stability, ensuring appropriate intervals between each dose. Based on the evidence, we do not recommend HDNF in the place of providing four doses of standard naloxone due to the higher cost, risk of precipitated withdrawal and limited evidence compared to standard IN and IM. All results must be taken into consideration with the inclusion of the lived experiences, individual requirements, and consent of PWUD as crucial factors. It is imperative to refrain from formulating decisions concerning PWUD in their absence, as their participation and voices should be integral to the decision-making process.

Differential risks of syringe service program participants in Central Ohio: a latent class analysis

BACKGROUND

Significant heterogeneity exists among people who use drugs (PWUD). We identify distinct profiles of syringe service program (SSP) clients to (a) evaluate differential risk factors across subgroups and (b) inform harm reduction programming.

METHODS

Latent class analysis (LCA) was applied to identify subgroups of participants (N = 3418) in a SSP in Columbus, Ohio, from 2019 to 2021. Demographics (age, sex, race/ethnicity, sexual orientation, housing status) and drug use characteristics (substance[s] used, syringe gauge, needle length, using alone, mixing drugs, sharing supplies, reducing use, self-reported perceptions on the impact of use, and treatment/support resources) were used as indicators to define latent classes. A five-class LCA model was developed, and logistic regression was then employed to compare risk factors at program initiation and at follow-up visits between latent classes.

RESULTS

Five latent classes were identified: (1) heterosexual males using opioids/stimulants with housing instability and limited resources for treatment/support (16.1%), (2) heterosexual individuals using opioids with stable housing and resources for treatment/support (33.1%), (3) individuals using methamphetamine (12.4%), (4) young white individuals using opioids/methamphetamine (20.5%), and (5) females using opioids/cocaine (17.9%). Class 2 served as the reference group for logistic regression models, and at the time of entry, class 1 was more likely to report history of substance use treatment, overdose, HCV, sharing supplies, and mixing drugs, with persistently higher odds of sharing supplies and mixing drugs at follow-up. Class 3 was more likely to report history of overdose, sharing supplies, and mixing drugs, but outcomes at follow-up were comparable. Class 4 was the least likely to report history of overdose, HCV, and mixing drugs, but the most likely to report HIV. Class 5 was more likely to report history of substance use treatment, overdose, HCV, sharing supplies, and mixing drugs at entry, and higher reports of accessing substance use treatment and testing positive for HCV persisted at follow-up.

CONCLUSIONS

Considerable heterogeneity exists among PWUD, leading to differential risk factors that may persist throughout engagement in harm reduction services. LCA can identify distinct profiles of PWUD accessing services to tailor interventions that address risks, improve outcomes, and mitigate disparities.