Cerebrovascular Correlates of Dementia in Community-dwelling Older Adults Living in Remote Rural Communities - The Three Villages Study. Methodology and Operational Definitions.

The Three Villages Study is a population-based prospective cohort study designed to reduce the increasing burden of cognitive decline and dementia in rural Ecuador. Before the study, our Executive Committee met with community leaders to explain the aims of the study and to learn about the culture and traditions of villagers. Field personnel were trained to assure uniformity in data collection. With the aid of satellite view (Google Earth, Google Inc., Mountain View, CA), updated sketches of the villages were performed to identify blocks and houses.

The study initially will follow a 3-Phase cross-sectional design. During Phase I, Atahualpa, El Tambo, and Prosperidad residents aged 60 years or more will be identified by means of a door-to-door survey and interviewed with validated questionnaires to identify those with relevant risk factors and suspected conditions of interest. In Phase II, certified neurologists will examine suspected cases as well as random samples of negative individuals, to assess reliability of field instruments and to determine prevalence of the investigated conditions. In Phase III, enrolled individuals will be invited to undergo complementary tests. Thereafter, incoming residents will be recruited and followed-up by means of yearly door-to-door surveys and other overlapping sources to estimate incidence of the disorders of interest.