Ethnographic strategies in the tracking and retention of street-recruited community-based samples of substance using hidden populations in longitudinal studies.

The article presents practical and methodological strategies in the tracking and retention of a longitudinal community-based sample of 300 Mexican American noninjecting users of heroin. Presented are the ethnographic strategies the research team utilized to maintain high retention rates among this highly marginalized and hidden population. Findings indicate that these ethnographic strategies are the basis for a reliable method for subject retention among drug-using populations. Further, the strategies illustrate how qualitative methods can complement the collection of quantitative data. Discussed is how these strategies can be used to identify and engage similar populations in research studies.