Courtney A McKnight
Courtney A McKnight
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Clinical Assistant Professor of Epidemiology
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Professional overview
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Dr. Courtney McKnight is a Principal Investigator specializing in mixed methods research focused on the epidemiology of drug use, opioid overdose, HIV and HCV infection. Dr. McKnight has over 20 years of experience conducting public health research related to drug use, as well as field experience as a harm reduction service provider.
Prior to joining NYU, Dr. McKnight served as the assistant director of research at the Chemical Dependency Institute at the Icahn School of Medicine at Mount Sinai, where she was an investigator and project director on numerous federally funded research studies, including evaluations of syringe services programs; investigations of the drivers that contribute to disparate rates of HIV and HCV; and interventions to increase access to HIV and HCV testing and care.
Previous to Dr. McKnight’s work in research, she directed a harm reduction program for women who use drugs and volunteered at a syringe services program in New Jersey.
Dr. McKnight received her DrPH from the City University of New York Graduate Center, her Master of Public Health from Hunter College, and her Bachelor of Arts in sociology from Rutgers University. Her dissertation examined the impact of Medicaid coverage of methadone and buprenorphine on treatment access for opioid dependent beneficiaries.
Dr. McKnight’s current research interests include examining the shifting landscape of illicit opioids, including the increasing prevalence of illicitly manufactured fentanyl, and risk environments of people who use drugs.
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Education
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BA, Women's Studies, Rutgers University, New Brunswick, NJMPH, Community Health Education, Hunter College, New York, NYDrPH, The City University of New York, New York, NY
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Areas of research and study
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Behavioral ScienceDrug addictionEpidemiologyHarm reductionHepatitisHIV/AIDSInfectious DiseasesMixed-Methods ResearchOpioidQualitative ResearchSocial epidemiologySubstance Abuse
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Publications
Publications
Anti-vaccine attitudes and COVID-19 vaccine status at the end of the U.S. public health emergency
AbstractChoi, J., Feelemyer, J., Choe, K., Lynch, K., McKnight, C., Yang, L. H., Jarlais, D. D., & Chang, V. W. (n.d.).Publication year
2025Journal title
VaccineVolume
55AbstractIntroduction: Despite the end of the federal COVID-19 public health emergency in May 2023, COVID-19 prevention remains a priority. This study investigates how public vaccination attitudes and perceived COVID-19 risks relate to vaccination status, aiming to identify factors associated with COVID-19 vaccination post-emergency. Methods: An online survey was conducted from April to May 2023 among a non-representative, nationally-based sample of MTurk workers. The primary outcome was COVID-19 vaccination status. Variables examined included anti-vaccine attitudes, health status, COVID-19 experiences, and sociodemographic factors. We created a composite measure of anti-vaccine attitudes from 15 items with three levels. Bivariate tests of association and multivariable logistic regression were performed. Results: A final sample of 989 adults were included in this analysis. In our multivariable model, individuals with higher anti-vaccine attitudes were less likely to be vaccinated against COVID-19 compared to those with low anti-vaccine attitudes (OR = 0.10, 95 % CI 0.04, 0.25). Those who identified as LGBQ+ (OR = 2.55, 95 % CI 1.32, 4.94), had chronic conditions (OR = 2.94, 95 % CI 1.43, 6.01) and had felt stigmatized from COVID-19 infections (OR = 3.33, 95 % CI 1.47, 7.58) were more likely to be vaccinated, even after adjusting for anti-vaccine attitudes. News source, perceived risk of contagion by contact, and long COVID-related factors were not significantly associated with vaccination status in the multivariable model. Discussion: Our findings highlight the persistent relationship between anti-vaccine attitudes and vaccination status in the “post-pandemic” era. Beyond vaccine attitudes, sexual orientation, chronic conditions, and stigmatization experiences may influence perceived need for protection. Stigma can sometimes reinforce social norms driving vaccination, but this effect is nuanced, particularly with anti-vaccine attitudes. To promote vaccine uptake, interventions should prioritize community support, counter misinformation, and enhance vaccine literacy. Building trust among vulnerable populations is essential, rather than relying on public health messaging that may reinforce social stigma.Engagement in hepatitis C virus cascade of care and factors associated with testing among people who inject drugs in Iran
AbstractKhezri, M., Tavakoli, F., Mehmandoost, S., Sharafi, H., Zamani, O., Bazrafshani, M. S., Nasiri, N., Mirzaei, H., Moameri, H., Haghdoost, A. A., McKnight, C., Des Jarlais, D., Karamouzian, M., & Sharifi, H. (n.d.).Publication year
2025Journal title
Harm Reduction JournalVolume
22Issue
1AbstractBackground: Understanding the hepatitis C virus (HCV) cascade of care (CoC) and factors associated with engagement is crucial for designing interventions for achieving HCV elimination. However, data on engagement in the HCV CoC among people who inject drugs (PWID) in the Middle East and North Africa remains limited. We examined the HCV CoC and factors associated with testing among Iranian PWID. Methods: We recruited PWID in 14 cities using respondent-driven sampling. PWID completed structured interviews capturing measures on socio-demographics, behaviors, and HCV CoC. We examined the self-reported numbers and proportions of individuals who ever tested for HCV, tested positive for HCV antibody, were diagnosed with HCV, initiated HCV treatment, and achieved sustained virologic response (SVR). Multivariable logistic regression models were built to assess factors associated with HCV antibody testing. Results: Of 2308 PWID, 23.1% had ever received an HCV antibody test, 13.9% received the HCV antibody test in the last year, 3.4% had tested positive for HCV antibodies, and 2.5% had received an HCV diagnosis. Of those diagnosed, 54.4% reported initiating treatment, and 31.6% had achieved SVR. HCV antibody testing was significantly associated with having knowledge about HCV transmission through sharing needle/syringe (adjusted odds ratio [aOR] 8.09; 95% confidence intervals [CI] 5.25, 12.48), living with HIV (aOR 4.15; 1.58, 10.92), no previous history of homelessness (aOR 1.89; 1.31, 2.72), history of arrest/incarceration (aOR 1.83; 1.26, 2.64), history of being diagnosed with any mental health problems (aOR 2.88; 1.79, 4.61), history of non-fatal overdose (aOR 1.51; 1.08, 2.10), receiving needle exchange programs in the last 12 months (aOR 6.20; 3.86, 9.93), opioid agonist treatment in the last six months (aOR 2.10; 1.39, 3.18), and having ever received HBV vaccine (aOR 2.31; 1.59, 3.35). Conclusions: We found a considerably low engagement in HCV CoC among PWID in Iran. Enhancing access to testing services for PWID, especially those with limited awareness of HCV transmission and those encountering structural challenges, is essential as the initial step in the HCV CoC. This improvement is vital for strengthening HCV elimination efforts in Iran.Harms associated with injecting in public spaces: a global systematic review and meta-analysis
AbstractKhezri, M., Kimball, S., McKnight, C., Rouhani, S., Bunting, A. M., Karamouzian, M., Ompad, D. C., & Des Jarlais, D. (n.d.).Publication year
2025Journal title
International Journal of Drug PolicyVolume
140AbstractBackground: Despite increasing backlash against harm reduction efforts and the need to understand the risk environments encountered by people who inject drugs (PWID), a quantitative systematic review on public injecting and associated health and drug-related outcomes is lacking. We aimed to summarize the global evidence on the prevalence and harms associated with injecting in public spaces. Methods: We searched MEDLINE, Embase, PsycINFO, CINAHL, Scopus, Global Health, and Web of Science from inception to March 21, 2024. We pooled data from included studies using random-effects meta-analyses to quantify the associations between recent (i.e., current or within the last year) public injecting and associated outcomes. Public injecting was defined as injecting in public or semi-public spaces, including streets, parks, and abandoned buildings. Risk of bias was assessed using the Joanna Briggs Institute's critical appraisal tool. Results: Of the 6144 initial records, 84 studies were eligible for inclusion. The pooled prevalence of recent public injecting was 48.85 % (95 % confidence intervals [CI] 43.87, 53.85). Public injecting was associated with increased odds of recent non-fatal overdose (odds ratio [OR] 2.51, 95 % CI 2.01, 3.13), HCV infection (OR 1.55, 95 % CI 1.18, 2.02), recent needle/syringe sharing (OR 2.41, 95 % CI 1.97, 2.94), recent sex work (OR 1.75, 95 % CI 1.03, 2.97), recent incarceration (OR 2.10, 95 % CI 1.78, 2.47), and recent unstable housing/homelessness (OR 4.23, 95 % CI 3.17, 5.65). Public injecting showed a statistically non-significant association with HIV infection (OR 1.41, 95 % CI 0.80, 2.46). Public injecting was also associated with a higher willingness to use supervised injection facilities (OR 2.66, 95 % CI 1.86, 3.80). Conclusion: Public injecting is prevalent among PWID and associated with various adverse drug- and health-related outcomes, highlighting the need for increased access to safe injection spaces. Findings support developing interventions to reduce harms from public injecting, such as addressing structural risks from law enforcement, expanding naloxone programs, and establishing overdose prevention centers. Housing interventions, in particular, could serve as an effective upstream strategy to reduce public injecting and related harms.Heroin, Fentanyl, Intentional Fentanyl Use and HIV Transmission in a Community-Recruited Sample of Persons Who Inject Drugs, New York City: 2021–2023
AbstractDes Jarlais, D. C., Weng, C. A., Feelemyer, J., Khezri, M., Reynoso, M., Kimball, S., Uuskula, A., & McKnight, C. (n.d.).Publication year
2025Journal title
AIDS and BehaviorAbstractWe examined drug use patterns and HIV transmission among persons who inject drugs (PWID) in New York City from 2021 to 2024. Modified respondent-driven sampling was used to recruit PWID from October 2021–February 2024. A structured questionnaire measured demographics, drug use behaviors and overdose experiences (within previous 6 months). Urinalysis was conducted for recent substance use and serum samples were collected for HIV antibody testing. HIV incidence was estimated using a previously published algorithm. We recruited 463 PWID; high percentages of participants reported problematic life circumstances including unstable housing (45%), food insecurity (67%) and drug use problems: 25% reported a recent non-fatal overdose and 55% daily injecting. Fentanyl use was detected in 86% of urinalyses, heroin in 67%, cocaine in 78%, heroin without fentanyl in 1%, and fentanyl and cocaine in 69%. A moderate number of PWID (24%) reported intentional fentanyl use, which was associated with increased food insecurity, unstable housing, injection frequency, cocaine use, and recent non-fatal overdoses and recent receptive syringe sharing. HIV seroprevalence was 6%; there were three likely seroconversions in 1052 total person-years at risk (PYAR) from March 2020 to the times of interviews; estimated HIV incidence rate was 0.19/100 PYAR, 95% CI 0.12–1.67. Despite the increased HIV risks associated with intentional fentanyl use, HIV transmission among PWID has remained low, comparable to pre-fentanyl and pre-COVID-19 levels. Continued monitoring of drug use patterns and increased services for intentional fentanyl use are needed.COVID-19 vaccination uptake and determinants of booster vaccination among persons who inject drugs in New York City
AbstractKhezri, M., McKnight, C., Weng, C. A., Kimball, S., & Des Jarlais, D. (n.d.).Publication year
2024Journal title
PloS oneVolume
19Issue
5AbstractBackground 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.Facilitators and barriers to monitoring and evaluation at syringe service programs
AbstractHealy, E., Means, A. R., Knudtson, K., Frank, N., Juarez, A., Prohaska, S., McKnight, C., Des Jarlais, D., Asher, A., & Glick, S. N. (n.d.).Publication year
2024Journal title
Harm Reduction JournalVolume
21Issue
1AbstractBackground: Syringe services programs (SSPs) provide harm reduction supplies and services to people who use drugs and are often required by funders or partners to collect data from program participants. SSPs can use these data during monitoring and evaluation (M&E) to inform programmatic decision making, however little is known about facilitators and barriers to collecting and using data at SSPs. Methods: Using the Consolidated Framework for Implementation Research (CFIR), we conducted 12 key informant interviews with SSP staff to describe the overall landscape of data systems at SSPs, understand facilitators and barriers to data collection and use at SSPs, and generate recommendations for best practices for data collection at SSPs. We used 30 CFIR constructs to develop individual interview guides, guide data analysis, and interpret study findings. Results: Four main themes emerged from our analysis: SSP M&E systems are primarily designed to be responsive to perceived SSP client needs and preferences; SSP staffing capacity influences the likelihood of modifying M&E systems; external funding frequently forces changes to M&E systems; and strong M&E systems are often a necessary precursor for accessing funding. Conclusions: Our findings highlight that SSPs are not resistant to data collection and M&E, but face substantial barriers to implementation, including lack of funding and disjointed data reporting requirements. There is a need to expand M&E-focused funding opportunities, harmonize quantitative indicators collected across funders, and minimize data collection to essential data points for SSPs.Hepatitis C treatment outcomes among people who inject drugs experiencing unstable versus stable housing: Systematic review and meta-analysis
AbstractKimball, S., Reynoso, M., McKnight, C., & Jarlais, D. D. (n.d.).Publication year
2024Journal title
PloS oneVolume
19Issue
4AbstractBackground The prevalence of hepatitis C virus (HCV) among people who inject drugs (PWID) is between 50–70%. Prior systematic reviews demonstrated that PWID have similar direct acting antiviral treatment outcomes compared to non-PWID; however, reviews have not examined treatment outcomes by housing status. Given the links between housing and health, identifying gaps in HCV treatment can guide future interventions. Methods We conducted a systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched six databases for articles from 2014 onward. Two reviewers conducted title/abstract screenings, full-text review, and data extraction. We extracted effect measures for treatment initiation, adherence, completion, success, and reinfection by housing status. Studies underwent quality and certainty assessments, and we performed meta-analyses as appropriate. Results Our search yielded 473 studies, eight of which met inclusion criteria. Only the treatment initiation outcome had sufficient measures for meta-analysis. Using a random-effects model, we found those with unstable housing had 0.40 (0.26, 0.62) times the odds of initiating treatment compared to those with stable housing. Other outcomes were not amenable for meta-analysis due to a limited number of studies or differing outcome definitions. Conclusions Among PWID, unstable housing appears to be a barrier to HCV treatment initiation; however, the existing data is limited for treatment initiation and the other outcomes we examined. There is a need for more informative studies to better understand HCV treatment among those with unstable housing. Specifically, future studies should better define housing status beyond a binary, static measure to capture the nuances and complexity of housing and its subsequent impact on HCV treatment. Additionally, researchers should meaningfully consider whether the outcome(s) of interest are being accurately measured for individuals experiencing unstable housing.COVID-19 vaccination and HIV transmission among persons who inject drugs during the first two years of the COVID-19 pandemic in New York City
AbstractDes Jarlais, D. C., Weng, C. A., Feelemyer, J., & McKnight, C. (n.d.).Publication year
2023Journal title
Harm Reduction JournalVolume
20Issue
1AbstractBackground: To examine COVID-19 vaccination and HIV transmission among persons who inject drugs (PWID) during the COVID-19 pandemic (2020–2022) in New York City (NYC). Methods: Two hundred and seventy five PWID were recruited from October 2021 to September 2022. A structured questionnaire was used to measure demographics, drug use behaviors, overdose experiences, substance use treatment history, COVID-19 infection, vaccination, and attitudes. Serum samples were collected for HIV, HCV, and SARS-CoV-2 (COVID-19) antibody testing. Results: Participants were: 71% male, the mean age was 49 (SD 11), 81% reported at least one COVID-19 immunization, 76% were fully vaccinated and 64% of the unvaccinated had antibodies for COVID-19. Self-reported injection risk behaviors were very low. HIV seroprevalence was 7%. Eighty-nine percent of the HIV seropositive respondents reported knowing they were HIV seropositive and being on antiretroviral therapy prior to the COVID-19 pandemic. There were two likely seroconversions in 518.83 person-years at risk from the March 2020 start of the pandemic to the times of interviews, for an estimated incidence rate of 0.39/100 person-years, 95% Poisson CI 0.05–1.39/100 person-years. Conclusions: There is concern that the COVID-19 pandemic disruptions to HIV prevention services and the psychological stress of the pandemic may lead to increased risk behavior and increased HIV transmission. These data indicate adaptive/resilient behaviors in both obtaining COVID-19 vaccination and maintaining a low rate of HIV transmission among this sample of PWID during the first two years of the COVID-19 pandemic in NYC.Field Testing the “Avoid the Needle” Intervention for Persons at Risk for Transitioning to Injecting Drug Use in Tallinn, Estonia and New York City, USA
AbstractJarlais, D. C., McKnight, C., Weng, C. A., Feelemyer, J., Tross, S., Raag, M., Org, G., Talu, A., & Uuskula, A. (n.d.).Publication year
2023Journal title
AIDS and BehaviorVolume
27Issue
11Page(s)
3767-3779AbstractThis study aimed to field tested the “Avoid the Needle” (AtN) intervention to reduce transitions from non-injecting to injecting drug use in two different epidemiological settings. Respondent driven sampling was used to recruit current non-injecting drug users (NIDUs) in Tallinn, Estonia in 2018-19 and in New York City (NYC) in 2019-20. Both persons who had never injected and persons who had previously injected but not in the last 6 months were eligible; a structured interview was administered, a blood sample collected, and the intervention administered by trained interventionists. We recruited 19 non-injectors from Tallinn and 140 from NYC. Participants in Tallinn were younger and had begun using drugs at earlier ages than participants in NYC. The primary drugs used in Tallinn were amphetamine, fentanyl, and opioid analgesics, while in NYC they were heroin, cocaine, speedball, and fentanyl. Six-month follow-up data were obtained from 95% of participants in Tallinn. The study was interrupted by COVID-19 lockdown in NYC, but follow-up data were obtained from 59% of participants. There were minimal transitions to injecting: 1/18 in Tallinn and 0/83 in NYC. There were significant declines in the frequencies of using readily injectable drugs (fentanyl, amphetamine, heroin, cocaine) from baseline to follow-up in both sites (Cochran-Armitage tests for trend, χ2 = 21.3, p < 0.001 for New York City; and χ2 = 3.9, p = 0.048 for Tallinn). Reducing transitions into injecting is a potentially very important method for reducing HIV transmission and other harms of drug use. Further investigation and implementation of AtN type interventions is warranted.Global epidemiology of abortion among female sex workers: a systematic review, meta-analysis, and meta-regression
AbstractKhezri, M., Tavakoli, F., Schwartz, S., Karamouzian, M., Sharifi, H., McKnight, C. A., Jarlais, D. D., Baral, S., & Shokoohi, M. (n.d.).Publication year
2023Journal title
Annals of EpidemiologyVolume
85Page(s)
13-37AbstractPurpose: Despite the evidence of a high rate of unintended pregnancy, there remains limited information about the prevalence and experiences of abortion among female sex workers (FSWs). In response, we aimed to summarize the available evidence on abortion among FSWs. Methods: We searched Medline, Embase, PsycINFO, CINAHL, Scopus, and Web of Science from inception to January 29, 2023. We pooled data from the included studies using random-effects meta-analyses. We also grouped countries for the legality of elective abortion stratified by the United Nations database on abortion laws and policies. Results: We identified 60 eligible studies from 2031 potentially eligible records. The pooled lifetime prevalence of at least one and multiple induced abortions was 37.7% (95% confidence interval, 31.8–43.7) and 21.7% (14.9–29.2), respectively. Among FSWs recruited in countries where elective abortion is illegal, at least one induced abortion prevalence was 35.1% (28.1–42.4), and multiple induced abortion prevalence was 23.1% (12.4–35.9). In countries where elective abortion is legal, at least one induced abortion prevalence was 44.6% (34.8–54.6), and multiple induced abortion prevalence was 19.9% (11.9–29.3). Among FSWs experiencing abortion, self-managed abortion prevalence was estimated at 32.8% (23.6–42.7) overall, 42.8% (37.2–48.5) for countries where elective abortion is illegal, and 15.6% (3.9–32.7) for countries that legally allow elective abortion. Conclusions: Induced abortion is prevalent among FSWs, highlighting the need for interventions to increase access to effective contraception and safe abortion care. While induced abortion prevalence did not significantly differ across the legal grounds for abortion, self-managed abortion prevalence was higher in countries where elective abortion was illegal, highlighting the urgent need for accessible abortion services for FSWs in criminalized settings. Moving forward necessitates implementing and evaluating culturally acceptable models of safe abortion and post-abortion care for FSWs to increase access to the full spectrum of sexual and reproductive health services.HIV risk and prevention among clients of a delivery-based harm reduction service during an HIV outbreak among people who use drugs in northern rural Minnesota, USA
AbstractPalayew, A., Knudtson, K., Purchase, S., Clark, S., Possehl, L., Healy, E., Deutsch, S., McKnight, C. A., Des Jarlais, D., & Glick, S. N. (n.d.).Publication year
2023Journal title
Harm Reduction JournalVolume
20Issue
1AbstractBackground: Since 2019, multiple HIV outbreaks occurred among people who inject drugs (PWID) in Minnesota. Syringe service programs (SSPs) are evidence-based programs that reduce the spread of HIV. We conducted an assessment of characteristics and HIV risk and prevention among clients of a delivery-based SSP near an HIV outbreak in rural, northern Minnesota. Methods: In the fall of 2021, we conducted a cross-sectional survey of clients of a mobile SSP based in Duluth, Minnesota. Survey topics included demographics, drug use, sexual behavior, HIV testing history, and HIV status. We conducted descriptive analyses and used univariate logistic regression to identify correlates of syringe sharing. The analysis was limited to PWID in the last six months. Results: A total of 125 people were surveyed; 77 (62%) were PWID in the last six months. Among these participants, 52% were female and 50% were homeless. Thirty-two percent reported sharing syringes and 45% reported sharing injecting equipment. Approximately one-half (49%) of participants had been tested for HIV in the past year, and none reported being HIV-positive. Individuals reported low condom usage (88% never used), and 23% of participants reported engaging in some form of transactional sex in the last six months. Incarceration in the last year was associated with sharing syringes (odds ratio = 1.4, 95% confidence interval 1.1–1.8). Conclusion: HIV risk was high among PWID receiving services at this SSP. These data highlight a rural SSP that is engaged with people at risk for HIV and needs additional support to expand harm reduction services.Understanding intentionality of fentanyl use and drug overdose risk: Findings from a mixed methods study of people who inject drugs in New York City
AbstractMcKnight, C., Weng, C. A., Reynoso, M., Kimball, S., Thompson, L. M., & Jarlais, D. D. (n.d.).Publication year
2023Journal title
International Journal of Drug PolicyVolume
118AbstractBackground: As the proportion of drug overdose deaths involving fentanyl continues to increase in the US, monitoring exposure to and possible changes in intention to use fentanyl among people who use drugs (PWUD) is of great public health importance. This mixed methods study examines intentionality of fentanyl use among persons who inject drugs (PWID) in New York City during a period of unprecedently high rates of drug overdose mortality. Methods: Between October 2021 and December 2022, N = 313 PWID were enrolled in a cross-sectional study that included a survey and urine toxicology screening. A subset of N = 162 PWID also participated in an in-depth interview (IDI) examining drug use patterns, including fentanyl use and experiences with drug overdose. Results: 83% of PWID were urine-toxicology positive for fentanyl, though only 18% reported recent intentional fentanyl use. Intentionality of fentanyl use was associated with being younger, white, increased drug use frequency, recent overdose (OD), recent stimulant use, among other characteristics. Qualitative findings suggest PWID tolerance to fentanyl may be increasing, which could result in an increased preference for fentanyl. Concern about overdose was common with nearly all PWID using overdose prevention strategies to avoid it. Conclusion: The findings from this study demonstrate a high prevalence of fentanyl use among PWID in NYC, despite an expressed preference for heroin. Our results suggest that the pervasiveness of fentanyl may be increasing fentanyl use and tolerance, which may contribute to an increased risk for drug overdose. Expanding access to existing evidence-based interventions such as naloxone and medications for opioid use disorder is necessary to reduce overdose mortality. Further, exploring the implementation of additional novel strategies to reduce the risk of drug overdose should be considered, including other forms of opioid maintenance treatment and expansion and government support for overdose prevention centers.Modeling HIV transmission among persons who inject drugs (PWID) at the “End of the HIV Epidemic” and during the COVID-19 pandemic
AbstractJarlais, D. D., Bobashev, G., Feelemyer, J., & McKnight, C. (n.d.).Publication year
2022Journal title
Drug and alcohol dependenceVolume
238AbstractBackground: We explore injecting risk and HIV incidence among PWID in New York City (NYC), from 2012 to 2019, when incidence was extremely low, <0.1/100 person-years at risk, and during disruption of prevention services due to the COVID-19 pandemic. Methods: We developed an Agent-Based model (ABM) to simulate sharing injecting equipment and measure HIV incidence in NYC. The model was adapted from a previous ABM model developed to compare HIV transmission with “high” versus “low” dead space syringes. Data for applying the model to NYC during the period of very low HIV incidence was taken from the “Risk Factors” study, a long-running study of participants entering substance use treatment in NYC. Injecting risk behavior had not been eliminated in this population, with approximately 15 % reported recent syringe sharing. Data for possible transmission during COVID-19 disruption was taken from previous HIV outbreaks and early studies of the pandemic in NYC. Results: The modeled incidence rates fell within the 95 % confidence bounds of all of the empirically observed incidence rates, without any additional calibration of the model. Potential COVID-19 disruptions increased the probability of an outbreak from 0.03 to 0.25. Conclusions: The primary factors in the very low HIV incidence were the extremely small numbers of PWID likely to transmit HIV and that most sharing occurs within small, relatively stable, mostly seroconcordant groups. Containing an HIV outbreak among PWID during a continuing pandemic would be quite difficult. Pre-pandemic levels of HIV prevention services should be restored as quickly as feasible.Recurrent Injecting Drug Use as a Mediator between Psychiatric Disorder and Non-Fatal Overdose
AbstractBarnes, D. M., Xu, S., Cleland, C. M., McKnight, C., & Des Jarlais, D. (n.d.).Publication year
2022Journal title
Substance Use and MisuseVolume
57Issue
8Page(s)
1248-1256AbstractBackground: Unintentional drug overdose has increased markedly in the United States. Studies document an association between psychiatric disorder and unintentional overdose; we extend this research through a preliminary test of a causal model of recurrent injection drug use mediating this relationship. Methods: In a cross-sectional study of 241 adults in New York City with a possible current substance use disorder, we conducted conventional and Imai’s mediation analyses to examine if psychiatric disorder is associated with increased prevalence of ever overdosing and if recurrent injection drug use mediates this association. Our cross-sectional data permit the first step of assessing causal models: testing if statistical associations are consistent with the model. Results: Fifty-eight percent of the sample endorsed previous psychiatric disorder diagnosis and 35.7% reported ever overdosing. Imai’s mediation analysis showed that, adjusting for covariates, the total association between psychiatric diagnosis and ever overdosing (adjusted prevalence difference [aPD] = 0.16, 95% CI 0.04–0.28) was composed of a direct effect (aPD = 0.09, 95% CI −0.03 − 0.21, p = 0.136) and an indirect effect (aPD = 0.07, 95% CI 0.02–0.13). Recurrent injecting drug use contributed to 42% (ratio of indirect effect to total effect; 95% CI 12 − 100%, p = 0.02) of the association between psychiatric diagnosis and ever overdosing. Conventional mediation analysis produced similar results. Conclusions: Our results provide a warrant for taking the necessary next step for assessing a causal model using longitudinal data, potentially providing a strong rationale for intervening on psychiatric disorders to stem overdose.Thick trust, thin trust, social capital, and health outcomes among trans women of color in New York City
AbstractHwahng, S. J., Allen, B., Zadoretzky, C., Barber Doucet, H., McKnight, C., & Des Jarlais, D. (n.d.).Publication year
2022Journal title
International Journal of Transgender HealthVolume
23Issue
1Page(s)
214-231AbstractIntroduction: Many trans women of color communities experience high HIV seroprevalence, extreme poverty, high rates of victimization and substance use, and poor mental health. Greater knowledge of trans women of color social capital may contribute toward more effective services for this marginalized population. Methods: These data come from a mixed-methods study that examined trans/gender-variant people of color who attended transgender support groups at harm reduction programs in NYC. The study was conducted from 2011 to 12, total N = 34. The qualitative portion was derived from six focus group interviews. Results: Two support groups stood out as exhibiting very strong alternative kinship structures. One group was comprised of immigrant trans Latinas, and the other group were trans women of African descent living with HIV. Both groups demonstrated ample cultivation of “trust capital” in the form of “thick trust” (bonding capital) and “thin trust” (bridging/linking capital) both inside and outside/beyond the support groups. Thick trust included the cultivation of intimacy, support in primary romantic relationships, and community leadership. Thin trust included networking with a variety of organizations, increased educational opportunities, and cultural production. Discussion: Participants “opened up to social capital” through the process of trusting as a series of (1) risks; (2) vulnerabilities; and (3) reciprocities. A solid foundation of thick trust resulted in a social, psychological, and emotional “base.” Upon this foundation, thin trust was operationalized resulting in positive material, economic, and quality-of-life outcomes, leading to an expanded space of capabilities.Is your syringe services program cost-saving to society? A methodological case study
AbstractDes Jarlais, D. C., Feelemyer, J., McKnight, C., Knudtson, K., & Glick, S. N. (n.d.).Publication year
2021Journal title
Harm Reduction JournalVolume
18Issue
1AbstractBackground: While there is a general acceptance among public health officials and policy-makers that syringe services programs can be effective in reducing HIV transmission among persons who inject drugs, local syringe services programs are often asked to provide economic justifications for their activities. A cost-effectiveness study, estimating the cost of preventing one HIV infection, would be the preferred methods for addressing this economic question, but few local syringe services programs have the needed data, staff and epidemiologic modeling resources needed for a cost–effectiveness study. We present a method for estimating a threshold value for the number of HIV infections prevented above which the program will be cost-saving to society. An intervention is considered “cost-saving” when it leads to a desirable health outcome a lower cost than the alternative. Methods: The research literature on the effectiveness of syringe services programs in controlling HIV transmission among persons who inject drugs and guidelines for syringe services program that are “functioning very well” were used to estimate the cost-saving threshold at which a syringe services program becomes cost-saving through preventing HIV infections versus lifetime treatment of HIV. Three steps are involved: (1) determining if HIV transmission in the local persons who inject drugs (PWID) population is being controlled, (2) determining if the local syringe services program is functioning very well, and then (3) dividing the annual budget of the syringe services program by the lifetime cost of treating a single HIV infection. Results: A syringe services program in an area with controlled HIV transmission (with HIV incidence of 1/100 person-years or less), functioning very well (with high syringe coverage, linkages to other services, and monitoring the local drug use situation), and an annual budget of $500,000 would need to prevent only 3 new HIV infections per year to be cost-saving. Conclusions: Given the high costs of treating HIV infections, syringe services programs that are operating according to very good practices (“functioning very well”) and in communities in which HIV transmission is being controlled among persons who inject drugs, will almost certainly be cost-saving to society.Hepatitis C incidence and prevalence among Puerto Rican people who use drugs in New York City
Toward the Interpretation of Positive Testing for Fentanyl and Its Analogs in Real Hair Samples: Preliminary Considerations
Alternative kinship structures, resilience and social support among immigrant trans Latinas in the USA
Geographic distribution of risk ("Hotspots") for HIV, HCV, and drug overdose among persons who use drugs in New York City: The importance of local history
Injection and Heterosexual Risk Behaviors for HIV Infection Among Non-gay Identifying Men Who Have Sex with Men and Women
Prescription opiate analgesics, heroin, HIV and HCV among persons who inject drugs in New York City, 2016-2018
Being “hooked up” during a sharp increase in the availability of illicitly manufactured fentanyl: Adaptations of drug using practices among people who use drugs (PWUD) in New York City
Cost-effectiveness of hepatitis C screening and treatment linkage intervention in US methadone maintenance treatment programs
Hepatitis C virus prevalence and estimated incidence among new injectors during the opioid epidemic in New York City, 2000–2017: Protective effects of non-injecting drug use