Sampling Males Who Inject Drugs in Haiphong, Vietnam: Comparison of Time-Location and Respondent-Driven Sampling Methods

• Published in: Journal of urban health Vol. 92; no. 4; pp. 744 - 757
• Main Authors: Tran, Hoang Vu, Le, Linh-Vi N., Johnston, Lisa Grazina, Nadol, Patrick, Van Do, Anh, Tran, Ha Thi Thanh, Nguyen, Tuan Anh
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-08-2015; Springer Nature B.V
• Subjects: Adult; AIDS Serodiagnosis - statistics & numerical data; Bias; Drug abuse; Epidemiology; Health Informatics; HIV; Human immunodeficiency virus; Humans; Male; Medicine; Medicine & Public Health; Men; Polls & surveys; Public Health; Reproducibility of Results; Risk factors; Sampling methods; Sampling Studies; Substance Abuse, Intravenous - epidemiology; Time Factors; Vietnam - epidemiology; Haiphong Vietnam; Vietnam; ISEW, Vietnam; HIV/AIDS; Time-location sampling; People who inject drugs; Respondent-driven sampling; Bio-behavioral surveillance
• ISSN: 1099-3460; 1468-2869
• DOI: 10.1007/s11524-015-9966-z

Accurate measurements of HIV prevalence and associated risk factors among hidden and high-risk groups are vital for program planning and implementation. However, only two sampling methods are purported to provide representative estimates for populations without sampling frames: time-location sampling (TLS) and respondent-driven sampling (RDS). Each method is subject to potential biases and questionable reliability. In this paper, we evaluate surveys designed to estimate HIV prevalence and associated risk factors among people who inject drugs (PWID) sampled through TLS versus RDS. In 2012, males aged ≥16 years who reported injecting drugs in the previous month and living in Haiphong, Vietnam, were sampled using TLS or RDS. Data from each survey were analyzed to compare HIV prevalence, related risk factors, socio-demographic characteristics, refusal estimates, and time and expenditures for field implementation. TLS (
n
 = 432) and RDS (
n
 = 415) produced similarly high estimates for HIV prevalence. Significantly lower proportions of PWID sampled through RDS received methadone treatment or met an outreach worker. Refusal estimates were lower for TLS than for RDS. Total expenditures per sample collected and number of person-days of staff effort were higher for TLS than for RDS. Both survey methods were successful in recruiting a diverse sample of PWID in Haiphong. In Vietnam, surveys of PWID are conducted throughout the country; although the refusal estimate was calculated to be much higher for RDS than TLS, RDS in Haiphong appeared to sample PWID with less exposure to services and required fewer financial and staff resources compared with TLS.