Transfer of sampling methods for studies on most-at-risk populations (MARPs) in Brazil

Abstract

The objective of this paper was to describe the process of transferring two methods for sampling most-at-risk populations: respondent-driven sampling (RDS) and time-space sampling (TSS). The article describes steps in the process, the methods used in the 10 pilot studies, and lessons learned. The process was conducted in six steps, from a state-of-the-art seminar to a workshop on writing articles with the results of the pilot studies. The principal investigators reported difficulties in the fieldwork and data analysis, independently of the pilot sampling method. One of the most important results of the transfer process is that Brazil now has more than 100 researchers able to sample MARPs using RDS or TSS. The process also enabled the construction of baselines for MARPS, thus providing a broader understanding of the dynamics of HIV infection in the country and the use of evidence to plan the national response to the epidemic in these groups.

Sampling Methodologies for Epidemiologic Surveillance of Men Who Have Sex with Men and Transgender Women in Latin America: An Empiric Comparison of Convenience Sampling, Time Space Sampling, and Respondent Driven Sampling

“…CS, TSS, and RDS have all been used for epidemiologic surveillance in Latin America, but evidence directly comparing the methods for MSM/TW recruitment is limited [37–48]. Researchers in Fortaleza, Brazil compared samples of MSM recruited using TSS and RDS during chronologically distinct recruitment periods (TSS in 2002 and RDS in 2005), finding that RDS recruited more participants from lower socioeconomic strata faster and at a lower cost than TSS [42].…”

Hazardous alcohol use among transwomen in a Brazilian city

“…Comparing RDS to Time Location Sampling (TLS), another sampling method that may be used for hard-to-reach populations, RDS identified many more MSM in Fortaleza of low socioeconomic status 1,14 , a population with more public health relevance, and an outcome observed in other studies 14 . For these and other reasons, the Brazilian government 15 and Centers for Disease Control and Prevention (CDC) 16 , in the United States, recommend RDS as the method of choice for biological and behavioral and surveillance among key populations.…”

HIV testing coverage among female sex workers, Brazil, 2016

“…Since the onset of HIV/AIDS epidemy in Brazil, in the 1980s, the prevalence of HIV has remained in levels below 1% in the general population has been "concentrated", with higher rates among key-populations, such as FSWs 9 . The prevalence rate of HIV for FSWs was estimated in some researches conducted in the country 10,11 , REV BRAS EPIDEMIOL 2019; 22(SUPPL 1): E190006.supl.1 being always much higher than the general female population 12 .…”