Measuring Current Drug Use in Female Sex Workers and Their Noncommercial Male Partners in Mexico: Concordance Between Data Collected From Surveys Versus Semi-Structured Interviews

ABSTRACT

Background: Self-reports are commonly used to assess prevalence and frequency of drug use, but it is unclear whether qualitative methods like semi-structured interviews are as useful at obtaining such information as quantitative surveys. Objectives: This study compared drug use occurrence and frequency using data collected from quantitative surveys and qualitative interviews. We also examined whether combining data from both sources could result in significant increases in percentages of current users and whether the concordance between the two sets of data was associated with the type of drug use, age, gender and socioeconomic status. Methods: Self- reports of recent marijuana, heroin, crack, cocaine, crystal/methamphetamine, inhalant, and tranquilizer use were collected using both methods from a cohort of Mexican female sex workers and their non-commercial male partners (n = 82). Results: Participants were significantly less likely to report marijuana, cocaine and tranquilizer use and frequency of use during the qualitative interviews than during the quantitative surveys. Agreement on frequency of drug use was excellent for crystal/methamphetamine, heroin and inhalant use, and weak for cocaine, tranquilizers and marijuana use. Older participants exhibited significantly higher concordance than younger participants in reports of marijuana and methamphetamine use. Higher monthly income was significantly associated with higher concordance in crack use but lower concordance with marijuana use. Conclusions: Although use of such data can result in an underreporting of drug use, qualitative data can be quantified in certain circumstances to triangulate and confirm the results from quantitative analyses and provide a more comprehensive view of drug use.

Keywords:

• Drug use
• measurement
• surveys
• qualitative interviews
• concordance
• female sex workers

Funding

This work was supported by the National Institute on Drug Abuse [Grant numbers R01DA027772, R36DA032376, and T32DA023356].

Declaration of interest

The authors report no conflicts of interest.

Glossary

• Computer-assisted personal interviewing (CAPI): An interviewing technique in which the respondent or interviewer uses a computer to answer the questions.

• Concordance: A state in which things agree and do not conflict with each other.

• Convergence: The collection and analysis of quantitative and qualitative data separately on the same phenomenon and then the different results are compared and contrasted during the interpretation.

• FSW: Female sex worker.

• Quantitizing: The assignment of numerical values to qualitative data.

• RDS: Respondent Driven Sampling, a form of snowball sampling which allows researchers to make estimates about hidden populations such as the three groups at highest risk for HIV/AIDS: injection drug users, sex workers, and men who have sex with men.

• Sensitivity: A measure of the proportion of actual positives that are correctly identified as such (e.g., the percentage of sick people who are correctly identified as having the condition). Also called the true positive rate.

• Specificity: A measure of the proportion of negatives that are correctly identified as such (e.g., the percentage of healthy people who are correctly identified as not having the condition). Also called the true negative rate.

Additional information

Notes on contributors

Lawrence A. Palinkas

Lawrence A. Palinkas, Ph.D., is the Albert G. and Frances Lomas Feldman Professor of Social Policy and Health and Chair of the Department of Child, Youth and Families in the School of Social Work at the University of Southern California. A medical anthropologist, his primary areas of expertise are mental health services research, behavioral health and prevention science. Dr. Palinkas is particularly interested in the sociocultural and environmental determinants of health and health-related behavior, child welfare and child mental health, translational and implementation science, immigrant and refugee communities, global health and health disparities, and health behavior in extreme environments and disasters.

Angela Robertson Bazzi

Angela Robertson Bazzi, PhD, MPH, is an Assistant Professor in the Department of Community Health Sciences at the Boston University School of Public Health. She received her doctorate in Global Health from the University of California, San Diego and completed postdoctoral training at the Harvard School of Public Health. Dr. Bazzi uses mixed quantitative and qualitative methods to understand drug use and sexual risk behaviors among socially marginalized populations. Her NIDA-funded research and training has focused on the social epidemiology of HIV/STIs among international migrants and deportees, people who inject drugs, and female sex workers and their partners in Mexico.

Jennifer L. Syvertsen

Jennifer L. Syvertsen, Ph.D., is an Assistant Professor in the Department of Anthropology at the Ohio State University in Columbus, Ohio. She is a medical anthropologist trained in epidemiology and global public health whose work focuses on socially marginalized populations, broadly addressing issues of gender, emotional wellbeing, structural vulnerability, and health disparities. She has used mixed ethnographic and epidemiologic methods to understand substance use, sexual risk, intimate partner violence, and HIV/AIDS in the United States, Mexico, and Kenya. Her current research examines how injection drug use shapes HIV risk in Nyanza, Western Kenya.

Monica D. Ulibarri

Monica D. Ulibarri, Ph.D., is Assistant Adjunct Professor of Psychiatry at the University of California, San Diego School of Medicine. Dr. Ulibarri received her B.A. in Psychology and Spanish from Claremont McKenna College, and her M.A. and Ph.D. in Clinical Psychology from Arizona State University. Her current research focuses on HIV prevention with highly vulnerable populations such as female sex workers, injection drug users, and high-risk couples along the Mexico-U.S. border, with an emphasis on how gender-based violence, mental health, and substance use intersect with HIV risk behaviors. She is also examining the commercial sexual exploitation of adolescent girls in San Diego County.

Daniel Hernandez

Daniel Hernandez, B.S., is currently a medical student at the University of California, Davis School of Medicine. His career interests include working with socioeconomically disadvantaged populations, intravenous drug users, and sex workers. He obtained a Bachelor of Science at the University of California, San Diego. His research experience includes working on projects related to HIV prevention and drug cessation efforts along the U.S.–Mexico border at the UC San Diego School of Medicine Division of Global Public Health, and opioid abuse at the Scripps Research Institute in La Jolla, California.

M. Gudelia Rangel

M. Gudelia Rangel, Ph.D., earned her doctorate in Health Sciences from the National Institute of Public Health of Mexico; a Master in Public Health and a Bachelor of Arts in Social Work from the Autonomous University of Baja California. Most of her academic research has been at the Colegio de la Frontera Norte in Tijuana, Baja California. She currently serves as Coordinator of the Comprehensive Strategy for Migrant Health in the Mexico Ministry of Health and is the Delegate to the U.S.-México Border Health Commission (USMBHC) representing Health Secretary Dr. José Angel Córdova.

Gustavo Martinez

Gustavo Martinez, M.D., is the Director of the Medical Unit of the Salud y Desarollo Comunitario de Ciudad Juarez A.C. (SADEC), which is a civil association in Ciudad Juarez that provides medical care to under-served populations. Although his primary responsibilities are clinical, Dr. Martinez has served as a key co-investigator on several NIDA-funded research collaborations, including Mujer Segura, Mujer Mas Segura and Proyecto Parejas, where he was responsible for overseeing participant recruitment and retention efforts.

Steffanie A. Strathdee

Steffanie A. Strathdee, PhD, is the 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. Dr. Strathdee is an infectious disease epidemiologist who focuses on HIV prevention in underserved, marginalized populations worldwide, including injection drug users, men having sex with men, and sex workers. She has published over 500 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.