Sampling hidden populations: lessons learned from a telephone-based study of persons recently diagnosed with HIV (PRDH)

Abstract

This paper describes a flexible, multi-stage, nonprobability sampling process used in a study of persons recently diagnosed as HIV-positive (PRDH). From July 2007 to June 2008, we used venue and chain-referral sampling strategies to recruit PRDH in the US. We sought equal distributions (n = 20) of eligible PRDH from four self-identified subgroups: gay or bisexual men (GBM), heterosexual men (HM), heterosexual women (HW), and male-tofemale transgender women (TGW). We categorized 30 sampling venues as websites, health clinics, or other networks. For 359 volunteer respondents, website venues proved more productive compared to health clinics and other sources. Website venues were most efficient for sampling recently diagnosed GBM and HW. Passive sampling methods were less effective in recruiting HM and TGW. Sampling approaches should be flexible and tailored to reach sub-categories within hidden populations. The sampling process itself produced valuable knowledge about social networks of hidden HIV populations.

Keywords:

• hidden populations
• subject recruitment
• HIV
• venue sampling
• chain-referral sampling
• qualitative methodology

Acknowledgement

This study was funded by the Centers for Disease Control and Prevention Grant #5UR6PS000341. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.

Notes

A handful (four or five) of screened and interviewed individuals gave mailing addresses for incentive checks that duplicated previously used addresses. We investigated further to verify that all were from one group home, thus explaining legitimate address duplication. One interviewed GBM respondent, after comparing his name, address, and HIV status to our list of participants in another of our studies, was found to be not truthful about his HIV diagnosis.

1. A handful (four or five) of screened and interviewed individuals gave mailing addresses for incentive checks that duplicated previously used addresses. We investigated further to verify that all were from one group home, thus explaining legitimate address duplication. One interviewed GBM respondent, after comparing his name, address, and HIV status to our list of participants in another of our studies, was found to be not truthful about his HIV diagnosis.