New York University School of Global Public Health, New York, NY, United States of America.
Haiphong University of Medicine and Pharmacy, Haiphong, Vietnam.
PLoS One. 2021 Nov 18;16(11):e0259983. doi: 10.1371/journal.pone.0259983. eCollection 2021.
To describe the use of large-scale respondent driven sampling (RDS) surveys to demonstrate the "end of an HIV epidemic" (HIV incidence < 0.5/100 person-years) among persons who inject drugs (PWID) in a middle-income country. Large sample sizes are needed to convincingly demonstrate very low incidence rates.
4 large surveys (Ns approximately 1500 each) were conducted among PWID in Hai Phong, Vietnam in 2016-2019. Respondent driven sampling (RDS) with a modification to add snowball sampling was used for recruiting participants. HIV incidence was measured through recency testing, repeat participants across multiple surveys and in a cohort study of PWID recruited from the surveys. RDS analytics (time to equilibria and homophilies for major variables) were used to assess similarities/differences in RDS only versus RDS plus snowball recruiting. Characteristics were compared among respondents recruited through standard RDS recruitment versus through snowball sampling. An overall assessment of the robustness of RDS to modification was made when adding a snowball sampling recruitment.
RDS recruiting was very efficient in the first 5 weeks of each survey with approximately 180 respondents recruited per week. Recruiting then slowed considerably, and snowball sampling (permitting an individual respondent to recruit large numbers of new respondents) was added to the existing RDS recruiting. This led to recruiting within 13-14 weeks of 1383, 1451, 1444 and 1268 respondents, close to the target of 1500 respondents/survey. Comparisons of participants recruited through standard RDS method and respondents recruited through snowball methods showed very few significant differences. RDS analytics (quickly reaching equilibria, low homophilies) were favorable for both RDS recruited and total numbers of participants in each survey. DRug use and Infections in ViEtnam (DRIVE) methods have now been officially adopted in other provinces.
RDS appears to be quite robust with respect to adding a modest number of participants recruited through snowball sampling. Large sample sizes can provide compelling evidence for "ending an HIV epidemic" to policy makers in a PWID population in a middle income country setting.
描述使用大规模应答驱动抽样（RDS）调查在中低收入国家的吸毒者（PWID）中展示“艾滋病疫情结束”（HIV 发病率<0.5/100 人年）的情况。需要大样本量才能令人信服地证明非常低的发病率。
2016-2019 年在越南海防市进行了 4 项大型调查（每个调查的样本量约为 1500 人）。使用 RDS 进行招募参与者，其中对其进行了修改，增加了雪球抽样。通过最近测试、在多个调查中的重复参与者以及从调查中招募的吸毒者队列研究来衡量 HIV 发病率。使用 RDS 分析（主要变量的平衡时间和同质性）来评估仅使用 RDS 与 RDS 加雪球招募的相似性/差异。比较了通过标准 RDS 招募与通过雪球抽样招募的受访者的特征。当添加雪球抽样招募时，对 RDS 进行修改的稳健性进行了总体评估。
在每个调查的前 5 周，RDS 招募非常有效，每周招募约 180 名受访者。然后招募速度明显放缓，并且添加了雪球抽样（允许一个受访者招募大量新受访者）来补充现有的 RDS 招募。这导致在 13-14 周内招募了 1383、1451、1444 和 1268 名受访者，接近每个调查招募 1500 名受访者的目标。通过标准 RDS 方法招募的参与者和通过雪球方法招募的受访者之间的比较显示，差异很小。RDS 分析（快速达到平衡，低同质性）对 RDS 招募和每个调查的总参与者人数都有利。越南吸毒和感染的 DRug（DRIVE）方法现已在其他省份正式采用。
在添加通过雪球抽样招募的少量参与者方面，RDS 似乎相当稳健。大样本量可以为中低收入国家的吸毒者人群的政策制定者提供令人信服的证据，证明“艾滋病疫情结束”。
