Inquérito sobre o HIV entre HSH no Brasil em 2016 usando respondent-driven sampling (RDS) : descrição dos métodos e dos diagnósticos do RDS

Introdução: Este artigo detalha os métodos utilizados na segunda Pesquisa Nacional de Vigilância Biológica e Comportamental (BBSS) do HIV, sífilis e hepatite B e C entre os homens que fazem sexo com homens no Brasil. Métodos: O método Respondent-driven Sampling (RDS) foi utilizado em 12 cidades em 2016. A amostra foi iniciada com cinco a seis sementes em cada cidade. Testes rápidos para o HIV, sífilis e Hepatite B e C foram oferecidos aos participantes. O software RDS Analyst com o estimador de amostragem sucessiva (SS) de Gile foi utilizado para ajustar os resultados como recomendado, gerando um peso para cada indivíduo para análises. Osdados das 12cidades foram unidos em um único banco e analisados usando as ferramentas de dados complexos do Stata 14.0, com cada cidade sendo tratada como seu próprio estrato. Resultados: A duração da coleta de dados variou de 5,9 a 17,6 semanas e 4.176 homens foram recrutados nas 12 cidades. Dois sites não alcançaram o tamanho da amostra alvo devido a uma demora de seis meses na aprovação local do Comitê de Ética. Todas as cidades atingiram a convergência na principal variável estudada (HIV). Conclusão: O BBSS foi representativo e concluído conforme planejado e dentro do orçamento. A descrição dos métodos aqui é mais detalhada do que o habitual, devido às novas ferramentas e requisitos de diagnóstico das novas diretrizes do STROBE-RDS.Introduction: This paper details the methods used in the second national Biological and Behavioral Surveillance Survey (BBSS) of HIV, syphilis, and hepatitis B and C among men who have sex with men in Brazil. Methods: Respondent-driven sampling (RDS) was used in 12 cities in 2016. The targeted sample size was initiated with five to six seeds in each city. HIV, syphilis, and Hepatitis B and C rapid tests were offered to participants. RDS Analyst with Gile’s successive sampling (SS) estimator was used to adjust results as recommended and a weight for each individual was generated for further analysis. Data for the 12 cities were merged and analyzed using Stata 14.0 complex survey data tools with each city treated as its own stratum. Results: Duration of data collection varied from 5.9 to 17.6 weeks. 4,176 men were recruited in the 12 cities. Two sites failed to achieve targeted sample size due to a six-month delay in local IRB approval. No city failed to reach convergence in our major outcome variable (HIV). Conclusion: The comprehensive BBSS was completed as planned and on budget. The description of methods here is more detailed than usual, due to new diagnostic tools and requirements of the new STROBE-RDS guidelines

Formative research to optimize respondent-driven sampling surveys among hard-to-reach populations in HIV behavioral and biological surveillance: lessons learned from four case studies.

Respondent-driven sampling (RDS) is widely adopted as a method to assess HIV and other sexually transmitted infection prevalence and risk factors among hard-to-reach populations. Failures to properly implement RDS in several settings could potentially have been avoided, had formative research been conducted. However, to date there is no published literature addressing the use of formative research in preparing for RDS studies. This paper uses examples from Banja Luka, Bosnia and Herzegovina; Bangkok, Thailand; Podgorica, Montenegro; and St Vincent's and Grenadine Islands, Eastern Caribbean; among populations of men who have sex with men, female sex workers, and injecting drug users to describe how formative research was used to plan, implement, and predict outcomes of RDS surveys and to provide a template of RDS-specific questions for conducting formative research in preparation for RDS surveys. We outline case studies to illustrate how formative research may help researchers to determine whether RDS methodology is appropriate for a particular population and sociocultural context, and to decide on implementation details that lead to successful study outcomes

Populations size estimations using SS-PSE among MSM in four European cities: how many MSM are living with HIV?

Although men who have sex with men (MSM) are considered at high risk for transmission of sexually transmitted infections, including HIV, there are few studies estimating the population size of MSM in Europe. We used network data from a survey of MSM in four cities to perform successive sampling-population size estimations (SS-PSE) to estimate MSM population sizes

Prevalence of sexually transmitted infections among men who have sex with men in Zagreb, Croatia.

We used respondent-driven sampling among men who have sex with men (MSM) in Zagreb, Croatia in 2006 to investigate the prevalence of HIV, other sexually transmitted infections and sexual behaviours. We recruited 360 MSM. HIV infection was diagnosed in 4.5%. The seroprevalence of antibodies to viral pathogens was: herpes simplex virus type-2, 9.4%; hepatitis A, 14.2%; hepatitis C, 3.0%. Eighty percent of participants were susceptible to HBV infection (HBs antigen negative, and no antibodies to HBs and HBc antigen). Syphilis seroprevalence was 10.6%. Prevalence of Chlamydia and gonorrhoea was 9.0%, and 13.2%, respectively. Results indicate the need for interventions to diagnose, treat and prevent sexually transmitted infections among this population

The 12 city HIV Surveillance Survey among MSM in Brazil 2016 using respondent-driven sampling: a description of methods and RDS diagnostics

ABSTRACT: Introduction: This paper details the methods used in the second national Biological and Behavioral Surveillance Survey (BBSS) of HIV, syphilis, and hepatitis B and C among men who have sex with men in Brazil. Methods: Respondent-driven sampling (RDS) was used in 12 cities in 2016. The targeted sample size was initiated with five to six seeds in each city. HIV, syphilis, and Hepatitis B and C rapid tests were offered to participants. RDS Analyst with Gile’s successive sampling (SS) estimator was used to adjust results as recommended and a weight for each individual was generated for further analysis. Data for the 12 cities were merged and analyzed using Stata 14.0 complex survey data tools with each city treated as its own stratum. Results: Duration of data collection varied from 5.9 to 17.6 weeks. 4,176 men were recruited in the 12 cities. Two sites failed to achieve targeted sample size due to a six-month delay in local IRB approval. No city failed to reach convergence in our major outcome variable (HIV). Conclusion: The comprehensive BBSS was completed as planned and on budget. The description of methods here is more detailed than usual, due to new diagnostic tools and requirements of the new STROBE-RDS guidelines