About

Alexandria Macmadu, PhD, is an Assistant Professor of Epidemiology at Brown University and a member of the People, Place and Health Collective. Her research is centered on substance use, particularly opioids and opioid use disorder, overdose prevention, harm reduction, and the social determinants of drug-related harms. She is a community-engaged researcher whose work aims to examine the social factors influencing drug use and overdose, investigate evidence-based strategies to mitigate drug-related harms, and promote justice and health equity among marginalized groups such as BIPOC communities, rural populations, and individuals affected by the criminal legal system. Dr. Macmadu has contributed extensively to the field with over 50 peer-reviewed publications and multiple book chapters, publishing in leading journals including The Lancet Public Health, JAMA Network Open, and the American Journal of Public Health. She also serves as a Scientific Advisor, Expert Advisor, and Associate Editor in her field, reflecting her active engagement in advancing harm reduction and public health strategies related to substance use and overdose prevention.

Research topics

• Medicine
• Political Science
• Virology
• Internal medicine
• Demography
• Sociology
• Social Science
• Emergency medicine
• Environmental health
• Pediatrics
• Public relations
• Medical emergency
• Psychology
• Medical education
• Business
• Pathology
• Intensive care medicine
• Nursing
• Pedagogy

Selected publications

• Sociodemographic Characteristics and Drug Use Practices Associated with Fentanyl Use Frequency Among People Who Use Drugs in Rhode Island

  Substance Use & Misuse · 2026-02-11

  articleSenior author

  BACKGROUND: Since 2013, fentanyl has dominated unregulated drug supplies in the northeast and has become a key driver of overdose deaths. In this analysis, we sought to identify the characteristics associated with fentanyl use frequency among people who use drugs in Rhode Island. METHODS: We examined baseline data from the Rhode Island Prescription and Illicit Drug Study, which enrolled participants from August 2020 to February 2023. We used an ordinal logistic regression to identify sociodemographic and drug use characteristics that were associated with prior month fentanyl use frequency, which was categorized as none, less than weekly, or at least weekly. RESULTS: 0.05) with greater fentanyl use frequency. CONCLUSIONS: Fentanyl exposure and intentional fentanyl use were common in the sample. Our findings suggest a need for increased investment in community-based harm reduction services and low-barrier, patient-centered treatment for polysubstance use, including those involving stimulant use disorders.

  PublisherDOI

• Sociodemographic Characteristics and Drug Use Practices Associated with Fentanyl Use Frequency Among People Who Use Drugs in Rhode Island

  Figshare · 2026-01-01

  articleOpen accessSenior author

  Since 2013, fentanyl has dominated unregulated drug supplies in the northeast and has become a key driver of overdose deaths. In this analysis, we sought to identify the characteristics associated with fentanyl use frequency among people who use drugs in Rhode Island. We examined baseline data from the Rhode Island Prescription and Illicit Drug Study, which enrolled participants from August 2020 to February 2023. We used an ordinal logistic regression to identify sociodemographic and drug use characteristics that were associated with prior month fentanyl use frequency, which was categorized as none, less than weekly, or at least weekly. Among 471 participants, 210 (44%) reported no prior month use of fentanyl or drugs containing fentanyl, 121 (26%) reported less than weekly use, and 140 (30%) reported at least weekly use. Of those who reported at least weekly use, 74% reported intentional use. In bivariate analyses, the proportion of participants utilizing harm reduction practices (e.g., fentanyl test strip use, naloxone carriage) increased with fentanyl use frequency in a dose-response manner. In adjusted analyses, prior month injection drug use, fentanyl preference, regular use of crack cocaine, lifetime overdose history, and current enrollment in opioid agonist therapy were significantly associated (<i>p</i>&lt; 0.05) with greater fentanyl use frequency. Fentanyl exposure and intentional fentanyl use were common in the sample. Our findings suggest a need for increased investment in community-based harm reduction services and low-barrier, patient-centered treatment for polysubstance use, including those involving stimulant use disorders.

  PublisherDOI

• Identification of distinct stimulant use trajectories and patterns of overdose

  Addictive Behaviors Reports · 2026-05-14

  articleOpen access

  • Four distinct stimulant use trajectories were identified over 12 months. • High stimulant use was associated with recent overdose and being unhoused. • Powder cocaine showed a unique declining pattern of use. • Diagnosed psychosis was associated with more days of recent stimulant use ( p < 0.05). • Findings may inform the design of tailored harm reduction interventions. Overdoses in the United States are increasingly driven by co-occurring stimulant and fentanyl use, yet limited research has examined individual-level stimulant use patterns over time. We assessed self-reported stimulant use among 505 people who use drugs enrolled in the Rhode Island Prescription and Illicit Drug Study (RAPIDS) from 2020 to 2024. Group-based trajectory modeling identified distinct patterns of past-month stimulant use over 12 months of follow-up. We examined associations between trajectories and sociodemographic characteristics, other substance use patterns, and mental health diagnoses. Four distinct stimulant use trajectories emerged: low (12%), low/moderate (52%), moderate/high (19%), and high (17%) use. The high-use group exhibited the highest proportion of people who were unhoused (82%, p < 0.01) and had injected drugs in the past month (42%, p < 0.01) at baseline. The high-use group also reported the highest proportions of a lifetime diagnosis of bipolar disorder (46%, p = 0.05), anxiety disorder (57%, p < 0.01), and psychosis (25%, p < 0.01) at baseline. Trajectory-based analyses by specific stimulant type revealed that powder cocaine decreased at three months compared to baseline, while other stimulant use (i.e., crack cocaine, crystal methamphetamine, extra-medical prescription stimulants) remained relatively stable over follow-up. Findings underscore the need for prevention and harm reduction-focused interventions in settings that serve people who are unhoused (e.g., living in homeless shelters, transitional programs) and those with diagnosed psychosis (e.g., receiving behavioral and mental health services).

  PublisherDOI

• Association of nonfatal overdose surveillance data with concurrent and future overdose deaths in Rhode Island

  American Journal of Epidemiology · 2026-01-26

  article

  Given substantial reporting delays in overdose deaths, state health departments increasingly use nonfatal overdose data to inform geographically targeted rapid overdose response efforts. We evaluated the extent to which nonfatal overdose events were associated with concurrent and future overdose deaths in Rhode Island. We aggregated nonfatal overdose data from emergency medical services records (2019-2023) and fatal overdose data from the State Unintentional Drug Overdose Reporting System (2020-2023) in 1-, 3-, and 6-month intervals at census block group and census tract levels. Rates of fatal overdose were estimated, relative to nonfatal overdose lagged by 0-12 months, using negative binomial regression, and relative to monthly spikes in nonfatal overdose burden, using zero-inflated Poisson regression. Estimation was implemented using integrated nested Laplace approximation. Each additional nonfatal overdose event per census block group was associated with fatal overdose rates that were 48% higher (95% credible interval, 1.37-1.59) than expected in concurrent months, with smaller associations at the census tract level, in wider time intervals, and when nonfatal overdose data were lagged. Spikes in nonfatal overdose activity were associated with elevated overdose mortality in concurrent periods with fine temporal and geographic granularity, but not in longer time frames and larger geographic areas.

  PublisherDOI

• Sociodemographic Characteristics and Drug Use Practices Associated with Fentanyl Use Frequency Among People Who Use Drugs in Rhode Island

  Figshare · 2026-01-01

  articleOpen accessSenior author

  Since 2013, fentanyl has dominated unregulated drug supplies in the northeast and has become a key driver of overdose deaths. In this analysis, we sought to identify the characteristics associated with fentanyl use frequency among people who use drugs in Rhode Island. We examined baseline data from the Rhode Island Prescription and Illicit Drug Study, which enrolled participants from August 2020 to February 2023. We used an ordinal logistic regression to identify sociodemographic and drug use characteristics that were associated with prior month fentanyl use frequency, which was categorized as none, less than weekly, or at least weekly. Among 471 participants, 210 (44%) reported no prior month use of fentanyl or drugs containing fentanyl, 121 (26%) reported less than weekly use, and 140 (30%) reported at least weekly use. Of those who reported at least weekly use, 74% reported intentional use. In bivariate analyses, the proportion of participants utilizing harm reduction practices (e.g., fentanyl test strip use, naloxone carriage) increased with fentanyl use frequency in a dose-response manner. In adjusted analyses, prior month injection drug use, fentanyl preference, regular use of crack cocaine, lifetime overdose history, and current enrollment in opioid agonist therapy were significantly associated (<i>p</i>&lt; 0.05) with greater fentanyl use frequency. Fentanyl exposure and intentional fentanyl use were common in the sample. Our findings suggest a need for increased investment in community-based harm reduction services and low-barrier, patient-centered treatment for polysubstance use, including those involving stimulant use disorders.

  PublisherDOI

• Concordance of Suspected, Self-Reported Co-Occurrence of Fentanyl With Other Drugs of Use and Urine Drug Testing Among People who use Drugs in Rhode Island

  Drug and Alcohol Dependence · 2025-02-01

  article
  PublisherDOI

• Synthetic Opioid and Stimulant Co-Involved Overdose Deaths by Occupation and Industry — United States, 2022

  MMWR Morbidity and Mortality Weekly Report · 2025-03-27 · 7 citations

  articleOpen access

  The proportion of synthetic opioid overdose deaths co-involving stimulants has increased in the United States in recent years. Although persons who use opioids have reported increasing stimulant co-use to maintain workplace productivity and alertness, occupational patterns of co-involvement in fatal overdose have not been systematically investigated. In an exploratory study, data on overdose deaths involving synthetic opioids (e.g., fentanyl) from the 2022 National Vital Statistics System were analyzed to characterize patterns of stimulant co-involvement among U.S. residents aged 15-64 years, stratified by decedents' usual occupation and industry. Of 69,893 fatal synthetic opioid overdoses, 53.6% involved stimulants. Occupation and industry groups with the highest percentages of synthetic opioid overdose deaths co-involving psychostimulants with abuse potential (psychostimulants) were typically physically demanding (e.g., construction and extraction occupations), whereas categories with highest percentages of cocaine co-involvement were generally less physically strenuous (e.g., business and financial occupations); these patterns might reflect differences in desired drug effects, cost, and geographic availability. Work-related interventions might be useful in preventing the development of substance use disorder by decreasing rates of occupational injuries and workplace stress, connecting workers with substance use disorder to treatment resources, and reducing fatal overdose through harm reduction.

  PublisherOA PDFDOI

• An Overdose Forecasting Dashboard for Local Harm-Reduction Response

  Health Promotion Practice · 2025-05-05 · 4 citations

  articleOpen access

  As the United States grapples with an ongoing overdose crisis, states and jurisdictions are adopting novel approaches to reduce overdose mortality. In one novel approach, public health researchers and leaders in Rhode Island leveraged the state's robust surveillance data and collaborations between government, academic, and community-based organizations (CBOs) to launch the PROVIDENT (PReventing OVerdose using Information and Data from the EnvironmeNT) project, a population-based randomized controlled research trial (NCT05096429) in December 2019. The PROVIDENT trial utilizes machine learning (ML) methods to identify neighborhoods at risk of future overdose deaths at the census-block-group level to inform community-level overdose prevention resource distribution. To disseminate the ML model predictions, our research team developed an interactive, online mapping dashboard in close collaboration with three statewide CBOs. We measured whether these organizations utilized the PROVIDENT dashboard to allocate harm-reduction services based on ML model predictions and collected information about their data-driven decision-making processes. This case study describes how we assembled and piloted this overdose forecasting dashboard for use by CBOs between November 2021 and August 2024. By measuring dashboard logins, completed surveys, and engagement with ongoing training, we illustrate how organizations utilized ML and surveillance data to inform their outreach efforts and generate valuable insights at a neighborhood level.

  PublisherOA PDFDOI

• Differences by race and ethnicity in drug use patterns, harm reduction practices and barriers to treatment among people who use drugs in Rhode Island

  Harm Reduction Journal · 2025-03-20 · 5 citations

  articleOpen accessSenior author

  BACKGROUND: As in much of the United States, there have been significant increases in overdose deaths among non-Hispanic Black and Hispanic/Latinx populations in Rhode Island over the past decade. Given the shifting dynamics of the overdose epidemic, there is an urgent need for focused interventions that address the specific needs of diverse communities. This study explores differences in drug use patterns, harm reduction behaviors and types and barriers to treatment by race and ethnicity. METHODS: This study utilized baseline data from the Rhode Island Prescription and Illicit Drug Study (RAPIDS). We assessed sociodemographic characteristics, drug use patterns, harm reduction practices, treatment type, and barriers to treatment in a cross-sectional analysis of people who use drugs (PWUD), stratified by race and ethnicity (non-Hispanic white, non-Hispanic Black, non-Hispanic other race, and Hispanic). Chi-square tests of independence and ANOVA tests were used to identify statistically significant differences by race and ethnicity. RESULTS: Among 509 participants, the median age was 43, and the majority were men (64%). Non-Hispanic Black participants reported significantly less regular use of unregulated opioids, such as heroin (10%) and fentanyl (12%), as compared to non-Hispanic white participants (39% and 33%, respectively). Non-Hispanic Black participants reported significantly less experience responding to overdoses: only 39% had ever administered naloxone and 34% had ever performed rescue breathing, as compared to 67% and 57% among non-Hispanic white participants, respectively. Despite significant differences in drug use patterns, there were few differences in harm reduction practices by race and ethnicity. Current treatment enrollment was highest among those who were non-Hispanic white (38%) and lowest among those who were non-Hispanic Black (7%). CONCLUSIONS: These findings suggest that there are differences in overdose response experience and treatment exposure between non-Hispanic Black PWUD and those belonging to other racial and ethnic groups, indicating a need for enhanced investment in overdose response education, naloxone distribution and treatment access for non-Hispanic Black PWUD.

  PublisherOA PDFDOI

• Long-term, bidirectional associations between depressive symptom severity and opioid use among people with HIV: A prospective cohort study

  Addictive Behaviors Reports · 2025-06-05

  articleOpen access1st authorCorresponding

  Background: The bidirectional relationships between opioid use and depressive symptom severity among people living with HIV (PLHIV) are poorly understood. We hypothesized that higher opioid use frequency would be associated with greater subsequent depressive symptom severity and that greater depressive symptom severity would be associated with higher subsequent opioid use frequency. Methods: We analyzed data from the Veterans Aging Cohort Study (VACS) - survey sample, a prospective cohort including PLHIV receiving care at 8 US Veterans Health Administration sites. From 2002 to 2018, we assessed past year opioid use frequency based on self-reported heroin and/or prescription opioid use at study entry and follow-up, as well as depressive symptom severity. Time-lagged, generalized estimating equation models were used to construct estimates of the association between opioid use frequency and subsequent depressive symptom severity, and vice versa, adjusting for key sociodemographic and clinical characteristics. Results: In final adjusted models that included 2033 PLHIV (98 % male), subsequent depressive symptom severity was greater (adjusted odds ratio [aOR] = 1.44, 95 % CI: 1.22,1.70) for those who used opioids at least monthly compared to those who never used, and the association between these variables appeared to follow a dose-response pattern. Similarly, subsequent opioid use frequency was higher (aOR = 1.38, 95 % CI: 1.17,1.62) for those with moderate depressive symptom severity compared to those with none. Conclusions: Enhanced access to screening for substance use disorders, harm reduction services, and medications for opioid use disorder may be warranted in settings that serve veteran PLHIV; strategies expanding access to mental health services may also be promising.

  PublisherDOI

Frequent coauthors

• Josiah D. Rich

  Rhode Island Hospital

  117 shared

• Brandon D. L. Marshall

  Brown University

  110 shared

• Traci C. Green

  Rhode Island Hospital

  82 shared

• Lauren Brinkley‐Rubinstein

  Duke University

  44 shared

• Eliana Kaplowitz

  Hunter College

  30 shared

• Scott E. Hadland

  Massachusetts General Hospital

  24 shared

• Jennifer G. Clarke

  Brown University

  22 shared

• William C. Goedel

  Brown University

  19 shared

Education

• Ph.D., Epidemiology

  Brown University

  2022

• M.S., Behavioral and Social Sciences

  Brown University

  2015

• B.A., Ethics

  Brown University

  2014