Respondent-driven sampling: characteristics associated with productive and non-productive recruitment
Tatiana Andreeva
Respondent-driven sampling: characteristics associated with productive and non-productive recruitment
Abstract
BACKGROUND: While studying the population of female sex workers (FSWs) in Ukraine using respondent-driven sampling (RDS) methodology, we noticed that seeds could generate recruitment chains different with regards to their length. We presumed that homogeneity among respondents could be associated with prolonging the recruitment chains. Therefore, this study aimed to explore if the tendency of forming long and short chains was related to specific characteristics of FSWs.
METHODS: The study employed data from a bio-behavioral survey among FSWs, conducted in 2009, which used RDS method to recruit 975 participants in six Ukrainian cities with four or five initial seeds. Pearson chi-square test was used to evaluate differences in 29 parameters (demonstrating different ways of client search, social interaction, health and behavior of FSWs) between respondents who were included in either five productive (≥80 participants) or 20 non-productive chains. Stratified analysis with multivariable adjusted logistic regression model was carried out to show the association of examined covariates with recruitment productivity.
RESULTS: The findings revealed that affiliation to any non-governmental organization (NGO) for FSWs and injection drug users (IDUs) was a significant interaction factor. For those who were not members of the NGOs, while controlling for other covariates in the model, older age, higher level of education, being current or previous drug user, not appealing to state clinics for treatment of sexually transmitted infections (STIs), and involvement in escort services had larger adjusted estimated odds of productive recruitment of FSWs in the study. On the other hand, for members of any NGOs for FSWs/IDUs, street-based way of client search was strongly associated with productive recruitment.
CONCLUSIONS: The results of this study suggest that members and non-members of NGOs for FSWs/IDUs have different characteristics that allow them performing productive recruitment. This should be considered while developing a sampling technique for studies of hard-to-reach populations.