A comparison of respondent-driven and venue-based sampling of female sex workers in Liuzhou, China
- Sharon S Weir1,
- M Giovanna Merli2,
- Jing Li3,
- Anisha D Gandhi1,
- William W Neely4,
- Jessie K Edwards1,
- Chirayath M Suchindran5,
- Gail E Henderson6,
- Xiang-Sheng Chen3
- 1The Carolina Population Center and the Department of Epidemiology in the Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- 2Sanford School of Public Policy, Duke Population Research Institute, and Duke Global Health Institute, Duke University, Durham, North Carolina, USA
- 3The National Center for STD Control and the Chinese Academy of Medical Sciences, Institute of Dermatology, Nanjing, Jiangsu, China
- 4Lake Forest Park, Washington, USA
- 5The Carolina Population Center and the Department of Biostatistics in the Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- 6Department of Social Medicine, The School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Correspondence to Dr Sharon S Weir, The Carolina Population Center and the Department of Epidemiology in the Gillings School of Global Public Health, Campus Box 8120, University of North Carolina at Chapel Hill, Chapel Hill, NC 27546, USA;
UNAIDS Report 2012 Guest Editors
Peter D Ghys
Geoff P Garnett
- Accepted 27 August 2012
Objectives To compare two methods for sampling female sex workers (FSWs) for bio-behavioural surveillance. We compared the populations of sex workers recruited by the venue-based Priorities for Local AIDS Control Efforts (PLACE) method and a concurrently implemented network-based sampling method, respondent-driven sampling (RDS), in Liuzhou, China.
Methods For the PLACE protocol, all female workers at a stratified random sample of venues identified as places where people meet new sexual partners were interviewed and tested for syphilis. Female workers who reported sex work in the past 4 weeks were categorised as FSWs. RDS used peer recruitment and chain referral to obtain a sample of FSWs. Data were collected between October 2009 and January 2010. We compared the socio-demographic characteristics and the percentage with a positive syphilis test of FSWs recruited by PLACE and RDS.
Results The prevalence of a positive syphilis test was 24% among FSWs recruited by PLACE and 8.5% among those recruited by RDS and tested (prevalence ratio 3.3; 95% CI 1.5 to 7.2). Socio-demographic characteristics (age, residence and monthly income) also varied by sampling method. PLACE recruited fewer FSWs than RDS (161 vs 583), was more labour-intensive and had difficulty gaining access to some venues. RDS was more likely to recruit from areas near the RDS office and from large low prevalence entertainment venues.
Conclusions Surveillance protocols using different sampling methods can obtain different estimates of prevalence and population characteristics. Venue-based and network-based methods each have strengths and limitations reflecting differences in design and assumptions. We recommend that more research be conducted on measuring bias in bio-behavioural surveillance.
Contributors SSW: Overall PI for the study, responsible for implementation of the venue-based arm, and primary writer of the manuscript. GM: Co-PI for the study with primary responsibility for the RDS arm, contributed to text of paper, and overall analysis. X-SC: Co-PI responsible for oversight of syphilis testing, field work, and implementation, contributed to interpretation of results and analysis. ADG: Responsible for RDSAT analysis and review of paper. WWN: Responsible for RDS-II CIs and review of paper. JKE: Responsible for multivariable analysis and review of paper. CMS: Responsible for overall technical oversight of all statistical issues and review of paper. JL: Responsible for interviewer training, day to day coordination of field work, data quality, review of manuscript, resolving data issues and data entry. GEH: Responsible for identification of study location, facilitating collaboration with people in China and review of manuscript.
Funding Funding for the China PLACE-RDS Comparison Study was provided by USAID under the terms of cooperative agreements GPO-A-00-03-00003-00 and GPO-A-00-09-00003-0; by NICHD through the UNC R24 ‘Partnership for Social Science Research on HIV/AIDS in China’ (R24 HD056670-01) and the Pre-Doctoral Training Programme at the Carolina Population Center (R24 HD50924), University of North Carolina; by UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) through the ‘WHO Rapid Syphilis Test Project (A70577)’; by the Duke University and University of North Carolina Center(s) for AIDS Research; and by the National Center for STD Control in China.
Competing interest The authors have no conflict of interest to declare. The opinions expressed are those of the authors and do not necessarily reflect the views of any government.
Ethics approval Ethics approval provided by the IRB at UNC-Chapel Hill, IRB at National Center for STD Control in China.
Provenance and peer review Commissioned; externally peer reviewed.
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