Binge Drug Use Independently Predicts HIV Seroconversion Among Injection Drug Users: Implications for Public Health Strategies

Abstract

Several studies have highlighted risk factors that cause HIV vulnerability among injection drug users (IDUs); these studies in turn have prompted public health officials to take action to minimize these risks. We sought to evaluate the potential association between binge drug use and HIV seroconversion and, subsequently, risk factors associated with binge drug use among a cohort of IDUs. To do this, we performed analyses of (1) associations with HIV seroconversion and (2) associations with binge drug use among participants enrolled in the Vancouver Injection Drug Users Study (VIDUS), a prospective cohort of IDU. Because serial measures for each individual were available, we undertook a time-updated Cox regression analysis to detect associations with HIV incidence and variables potentially associated with binge drug use were evaluated by using generalized estimating equations (GEE). Overall, 1548 IDU were enrolled into the VIDUS cohort between May 1996 and May 2003. There were 1013 individuals who were HIV seronegative at enrollment and had at least one follow-up visit; 125 (12%) became HIV positive during the study period for a cumulative incidence rate of 14% at 64 months after enrollment. In the final multivariate model, binge drug use [Adjusted Hazards Ratio: 1.61 (CI: 1.12, 2.31)] was independently associated with HIV seroconversion. In subanalyses, when we evaluated associations with binge drug use in GEE analyses, borrowing [Odds Ratio (OR): 153 (CI: 1.33–1.76)] and lending [OR: 1.73 (CI: 1.50–1.98)] syringes, sex trade work [OR: 1.14 (CI: 1.01–1.29)], frequent cocaine [OR: 2.34 (CI: 2.11–2.60)] and heroin [OR: 1.29 (CI: 1.17–1.43)] injection were independently associated with binge drug use and methadone [OR: 0.80 (CI: 0.71–0.89)] was protective against binge drug use. Our study identified an independent association between binge drug use and HIV incidence and demonstrated several high-risk drug practices associated with bingeing. Given the unaddressed public health risks associated with bingeing, a public health response protocol must be developed to minimize the personal and public health risks associated with the binge use of drugs.

Keywords:

• HIV transmission
• binge drug use
• injection drug use
• public health
• vulnerability
• protective factors

Additional information

Notes on contributors

Cari L. Miller

Cari Miller, MSc, is currently in the final year of her PhD in Interdisciplinary Studies at the University of British Columbia. Her research interests include combined quantitative and qualitative methods, youth, injection drug use and blood borne infection prevention. Cari is supported by a Canadian Graduate Scholarship and by a PhD award through the Michael Smith Foundation for Health Research.

Thomas Kerr

Thomas Kerr, PhD, Dr. Thomas Kerr, PhD, is a Research Associate at the British Columbia Centre for Excellence in HIV/AIDS, where he is a co-principle investigator of the Vancouver Injection Drug Users Study and with the Scientific Evaluation of Vancouver's Supervised Injection Sites. Dr. Kerr has extensive research experience in the areas of health psychology and public health, especially in evaluating programs and treatments designed to address HIV/AIDS and injection drug use.

James C. Frankish

James C. Frankish, PhD, is studying how health authorities are addressing non-medical determinants of health. He is developing and testing tools to provide evidence-based evaluation of community-level effects resulting from population health initiatives. A particular focus is inclusion of vulnerable populations in these initiatives and related policy and practice implications. Dr. Frankish is also the leader of the MSFHR/CIHR program for Transdisciplinary Training in Community Partnership Research: Bridging Research to Practice, which is co-funded by the Michael Smith Foundation for Health Research and the Canadian Institutes of Health Research.

Patricia M. Spittal

Patricia M. Spittal, PhD, is a medical anthropologist by training. Her interests include indigenous populations, HIV/AIDS, injection drug use, and gender issues. She is currently the principle investigator of the CEDAR project, a project involving Aboriginal youth who use illicit drugs in British Columbia and a project in Uganda exploring HIV vulnerabilities in the north among displaced persons.

Kathy Li

Kathy Li, MSc, received her Masters degree in Statistics at the University of British Columbia in 1998. Her interests include biostatistics and epidemiology. She is currently involved in various projects including the Vancouver Injection Drug User Study and other related observational studies.

Martin T. Schechter

Martin Schechter, MD, PhD, is Professor and Head of the Department of Health Care and Epidemiology at the University of British Columbia, and is a tier I Canada Research Chair in HIV/AIDS and Urban Population Health. Dr. Schechter combines interests in clinical epidemiology and health services research with HIV/AIDS and urban health research. He is both a founder and National Director of the Canadian HIV Trials Network. Dr. Schechter is also Director of Epidemiology and Population Health at the BC Centre for Excellence in HIV/AIDS, and is Director of the Centre for Health Evaluation and Outcome Sciences.

Evan Wood

Evan Wood, PhD, is an Assistant Professor in the Department of Medicine at the University of British Columbia and is a Research Scientist at the British Columbia Centre for Excellence in HIV/AIDS where he is the co-Principal Investigator of the Vancouver Injection Drug Users Study (VIDUS) cohort and co-Principal Investigator of the Scientific Evaluation of Vancouver's Supervised Injection Sites which is funded through Health Canada. Dr. Wood has extensive research experience in the area of clinical epidemiology, especially in evaluating the treatment of HIV/AIDS, and epidemiologic study design, especially among drug using populations.