Sampling Designs for HIV Molecular Epidemiology with Application to Honduras

Abstract

Proper sampling is essential to characterize the molecular epidemiology of human immunodeficiency virus (HIV). HIV sampling frames are difficult to identify, so most studies use convenience samples. We discuss statistically valid and feasible sampling techniques that overcome some of the potential for bias due to convenience sampling and ensure better representation of the study population. We employ a sampling design called stratified cluster sampling. This first divides the population into geographical and/or social strata. Within each stratum, a population of clusters is chosen from groups, locations, or facilities where HIV-positive individuals might be found. Some clusters are randomly selected within strata and individuals are randomly selected within clusters. Variation and cost help determine the number of clusters and the number of individuals within clusters that are to be sampled. We illustrate the approach through a study designed to survey the heterogeneity of subtype B strains in Honduras.

Association of Herpes Simplex Virus Type 2 Infection and Syphilis with Human Immunodeficiency Virus Infection among Men Who Have Sex with Men in Peru

“…This is reflected in the diverse study population composition based on self-reported sexual identity (table 1). To ensure better representation of this MSM study population, future sampling should consider the implementation of stratified cluster sampling techniques, as described elsewhere [35]. Second, given that 12 different clinic sites and hundreds of field personnel participated in the surveys in all 6 cities, it is possible that differences in volunteer recruitment and study interview administration may have existed.…”

Transmitted drug resistance and type of infection in newly diagnosed HIV-1 individuals in Honduras

“…The demographics of the study population closely matched that of the published sampling design. 29 The median age of the study population was 31 years (range 15-64 years); 53% were male and 47% were female. The predominant route of HIV transmission was heterosexual (86%), 132 samples were from the general population, 11 samples from FSW and 29 samples from Garifunas; and the remaining 28 samples were collected from MSM.…”

“…To ensure a good representation of the population with HIV-infected persons in Honduras, we followed a published sampling strategy for representative HIV genotyping studies in Honduras. 29 The study included samples from general population, Garifunas (an ethnic group of African descent that migrated from Caribbean islands to the northern coast of Honduras), men who have sex with men (MSM) and female sex workers (FSW). Samples from the general population were collected using a convenience sampling strategy in the three major clinical centers of the country, Centro de Salud Miguel Paz Barahona in San Pedro Sula, Hospital Escuela and Instituto Nacional del Tórax in Tegucigalpa.…”

Cohort Profile: Caribbean, Central and South America Network for HIV research (CCASAnet) collaboration within the International Epidemiologic Databases to Evaluate AIDS (IeDEA) programme

“…Statistical methods to be developed for CCASAnet include sensitivity analysis approaches for causal inference, 17 techniques for adjusting lab variables to enable fairer cross-site comparison, 18 and unbiased and efficient sampling methods for studying the molecular epidemiology of HIV. 19 What is the attrition rate likely to be?…”