Strategies behind the establishment of a developmental cohort study in the Tottori City.

Background: The Tottori study group, part of the JCS, presides over a community-based cohort study started when subjects-children living in Tottori City-were 5 years old. The social aspects of conducting a cohort study should also be made public, as this information is crucial for conducting community-based cohort studies.

Methods: Documents pertaining to social aspects implemented by the Tottori study group between 2004 and 2008 were arranged chronologically.

Live birth prevalence of Down syndrome in Tottori, Japan, 1980-1999.

One hundred sixty-four patients with Down syndrome (DS) were confirmed in Tottori Prefecture, Japan, from 1980 to 1999. The sex ratio of 1.52 (99 males and 65 females) was comparable to that reported in previous studies.