![Sample our Health and Social Care journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5938/TOC-Subject-Sample-2021-Health-Social-Care.jpg"})
Abstract
Background: Although most people who inject drugs (PWID) in Tijuana, Mexico, primarily inject heroin, injection and non-injection use of methamphetamine and cocaine is common. We examined patterns of polydrug use among heroin injectors to inform prevention and treatment of drug use and its health and social consequences. Methods: Participants were PWID residing in Tijuana, aged ≥18 years who reported heroin injection in the past six months and were recruited through respondent-driven sampling (n = 1,025). Latent class analysis was conducted to assign individuals to classes on a probabilistic basis, using four indicators of past six-month polydrug and polyroute use: cocaine injecting, cocaine smoking or snorting, methamphetamine injecting, and methamphetamine smoking or snorting. Latent class membership was regressed onto covariates in a multinomial logistic regression. Results: Latent class analyses testing 1, 2, 3, and 4 classes were fit, with the 3-class solution fitting best. Class 1 was defined by predominantly heroin use (50.2%, n = 515); class 2 by methamphetamine and heroin use (43.7%, n = 448), and class 3 by methamphetamine, cocaine, and heroin use (6.0%, n = 62). Bivariate and multivariate analyses indicated a group of methamphetamine and cocaine users that exhibited higher-risk sexual practices and lower heroin injecting frequency, and a group of methamphetamine users who were younger and more likely to be female. Conclusions: Discrete subtypes of heroin PWID were identified based on methamphetamine and cocaine use patterns. These findings have identified subtypes of heroin injectors who require more tailored interventions to reduce the health and social harms of injecting drug use.
THE AUTHORS
Meredith C. Meacham, MPH, is a substance use epidemiologist and PhD Candidate in the UCSD–SDSU Joint Doctoral Program in Public Health, Global Health Track. She received her MPH in Public Health Genetics from the University of Washington and AB in Political Science from the University of Chicago. She is also a former Fulbright Fellow at the European Monitoring Centre for Drugs and Drug Addiction. Her previous research includes studying gene–environment interaction in the development of alcohol and tobacco use disorders with the UW Social Development Research Group and exploring researcher motivations for handling ethical dilemmas in genetic research. Her current research focuses on using latent class and latent transition analyses to model polydrug use and its association with HIV risk and overdose on both sides of the US–Mexico border. Her other interests include migration and mental health, international student exchange, drug policy, and longitudinal data analysis
Dr. Abby E. Rudolph, PhD, is a research scientist at the Pacific Institute for Research and Evaluation (PIRE) and an associate faculty member in the Health Behavior and Society Department at Johns Hopkins University Bloomberg School of Public Health. She received her PhD in infectious disease epidemiology from Johns Hopkins University Bloomberg School of Public Health in 2011 and her MPH from Columbia University Mailman School of Public Health in 2007. Dr. Rudolph's research focuses on understanding how individual, environmental, and network factors act together to shape disease transmission dynamics, risk behaviors, and health service use among populations disproportionately burdened with disease. Her publications cover a variety of topics, including HIV and drug use-related stigmas, recruitment strategies for “hidden” populations, network, and neighborhood/spatial correlates of HIV/STIs and related risk behaviors, innovative methods for measuring the independent and combined influence of spatial and network factors on recruitment dynamics and risk/health-seeking behaviors, expanding syringe access for people who inject drugs, and community-based participatory interventions to connect marginalized populations with health services
Dr. Steffanie A. Strathdee is associate dean of Global Health Sciences, Harold Simon Professor and chief of the Division of Global Public Health in the Department of Medicine at the University of California, San Diego School of Medicine. She is also an adjunct professor at the Johns Hopkins University. Dr. Strathdee is an infectious disease epidemiologist who has spent the last two decades focusing on HIV prevention in underserved and marginalized populations in developed and developing countries, including injection drug users, men having sex with men, and sex workers. In the last decade, she has published over 481 peer-reviewed publications on HIV prevention and the natural history of HIV and related infections and the evaluation of interventions to reduce harms among substance using populations. Currently, she is engaged in a number of HIV/STI prevention projects in international settings, including Mexico, India, Canada, and Afghanistan. She also leads three NIH-funded studies of HIV risk behaviors among drug users and sex workers on the Mexico–US border, one of which is funded through 2020 by a MERIT award granted by the National Institute on Drug Abuse
Dr. Melanie A. Rusch, PhD. is an infectious disease epidemiologist with the Vancouver Island Health Authority. She received her MSc from Johns Hopkins Bloomberg School of Public Health in Baltimore, and her PhD from the University of British Columbia in Vancouver, Canada. Her research has included longitudinal analysis of sexual behaviors among injection drug users, influence of types and patterns of drug use on sexually transmitted infections (STIs), and barriers to sexual health care, including STI-related stigma among women. During her doctoral training, Melanie also spent two years as a trainee in the Partnerships for Community-Based Health Research program, and was a part-time research assistant at the BC Centre for Excellence in HIV/AIDS for four years. Her current interests include examining broader influences on substance use and STIs, including social network factors and spatial aspects of disease transmission. In addition, Dr. Rusch is interested in improving accessibility of STI treatment and identifying structural barriers to sexual health care
Dr. Kimberly C. Brouwer, PhD, is currently an associate professor at the UCSD Division of Global Public Health. Her focus of work is in spatial epidemiology as it related to infectious epidemiology, and especially HIV/AIDS and injection drug use. She finished her PhD in molecular epidemiology in 2000 from Johns Hopkins University School of Hygiene and Public Health and BA in integrative biology from the University of California, Berkeley in 1994. Before joining UCSD as a post-doctoral fellow in 2004, she was a research fellow and guest researcher with the CDC for two years. She is co-director of the Global Health Track of the SDSU/UCSD Joint Doctoral Program in Public Health
Dr. Thomas L. Patterson received his PhD in comparative psychology from the University of California, Riverside in 1977. Since that time he has conducted research in a number of areas, including HIV/AIDS prevention, rehabilitation of older patients with psychosis, and stress responses of caregivers of Alzheimer's disease patients. He has authored or co-authored over 400 scholarly papers, 17 book chapters, and a widely used textbook on human behavior. He was a founding editor of the journal AIDS and Behavior and has served as a co-editor and on the editorial boards of a number of other journals
Dr. Patterson has been conducting psychosocial research with HIV+ and “at risk” populations since 1989.
Dr. Alicia Vera obtained her PhD degree from the Universidad Autónoma de Baja California (UABC), México, Summa Cum Laude. Her doctoral research explored injection drug users’ access to HIV prevention services at drug rehabilitation centers in Tijuana. Dr. Vera was highly productive as an AITRP pre-doctoral fellow, generating 20 manuscripts and four scholarly abstracts. She also produced three manuscripts from her dissertation. Prior to commencing her doctoral studies, Dr. Harvey Vera worked as a project director on a number of binational HIV/STI natural history and prevention studies with high-risk and marginalized populations (drug users, female sex workers, and immigrants) in Tijuana and Ciudad Juarez
Dr. Gudelia Rangel earned her PhD in health sciences from the National Institute of Public Health of Mexico, a Master's in public health and a Bachelor of Arts in Social Work from the Autonomous University of Baja California. Dr. Rangel has a distinguished public and academic career in health public policy, research, and teaching. In her academic career, she has conducted research on public health issues such as HIV/AIDS, reproductive health, access to health services, substance abuse, obesity, health and migration, and border health. Most of her academic research has been at the Colegio de la Frontera Norte in Tijuana, Baja California, where she served as Director for Population Studies, 2003 to 2004, and as General Director of Academic Affairs, 2004 to 2007. In the field of public health, she served as the coordinator of the Baja California Outreach Office, Mexico section of the U.S.–Mexico Border Health Commission, 2007 to early 2011. She currently serves as deputy general director for migrants’ health from the ministry of health besides being the executive secretary of U.S.–México Border Health Commission, Mexico section
Dr. Scott C. Roesch received his Bachelor of Science in psychology with a math emphasis at UC Davis. He then went on to receive his Master's in Arts in psychology at CSU Long Beach. From there he attended University of Nebraska-Lincoln to receive his PhD. in psychology. Dr. Roesch has been working on research in the area of stress and coping and currently teaches graduate statistic courses. He also works for the Child and Adolescent Services Research Center, Children's Hospital as a methodological and statistical core research scientist. Research interests include trait-state models of stress and coping; coping with physical illness, and particularly cancer; cultural, ethnic, and acculturation differences in stress and coping; cross-ethnic measurement equivalence; structural equation modeling, and meta-analysis
GLOSSARY
LCA: Latent Class Analysis, a mixture modeling technique for probabilistically assigning individuals to latent unobserved classes based on responses to a set of observed indicators.
PWID: People who inject drugs, previously termed as injection drug users (IDUs).
RDS: Respondent-Driven Sampling, a recruitment approach that uses an incentive-based peer referral strategy.
Recruitment Homophily: Propensity for people to recruit others with similar characteristics.