The feasibility of respondent-driven sampling with people who use drugs in rural Western Cape, South Africa: A qualitative study.

The Western Cape is South Africa's epicentre for tuberculosis (TB) and smoked drug use such as methamphetamine and methaqualone (Mandrax). Despite this, there are limited studies on people who smoke drugs (PWSD) with TB disease in South Africa, partly due to recruitment challenges. Respondent-driven sampling (RDS) is a network-based sampling method used to recruit such key populations. The aim of this qualitative study is to explore the appropriateness and feasibility of RDS as a method for recruiting PWSD for a planned study on TB transmission in this setting. We conducted ten focus group discussions (n = 84) with men and women from Worcester, a rural town in the Western Cape, who self-reported current methamphetamine and/or methaqualone use. Participants were recruited through an existing TB study or community-based outreach. Discussion topics included use of illicit drugs within social networks, feasibility of using RDS methods for recruiting PWSD, and logistical recommendations for the use of RDS and planned study participation. Data were analyzed using thematic analysis. Results indicate drug use by participants across large social networks which is favorable for RDS methods. The key themes were: 1) drug-use social network characteristics including demographic and geographic differences; 2) perspectives of PWSD on RDS methods; 3) potential challenges to proposed RDS recruitment and participation in a larger research study for PWSD, and 4) participant recommendations to enhance the uptake of RDS and study participation by PWSD. RDS seems to be a feasible method to recruit PWSD and improve the possibility of reaching a diverse sample of PWSD, with clear recommendations from participants regarding how to recruit participants for larger research studies. The current study indicates that conducting formative, qualitative research can assist researchers with RDS study design and planning for additional study activities. Trial Registration: ClinicalTrials.gov NCT041515602.