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. Information which is crucial for conducting community-based cohort studies were extracted and classified into several categories. RESULTS: Five categories were extracted from the documents: research staff, supporting committee, recruitment, maintenance of motivation and disclosure. Implementation of the social aspects described in maintenance of motivation resulted in fewer subjects dropping out of the study and a re-recruitment rate of approximately 90%. CONCLUSIONS: The following factors are essential for a successful developmental cohort study of children: 1) A birth cohort study should be planned in hospitals with medical staff such as obstetricians and pediatricians; 2) An interdisciplinary group composed of medical or psychological clinicians and researchers with abundant experience in epidemiological study should be included; 3) If possible, an expert or widely known individual in the study's target field should be included as a member of the study staff; 4) For long cohort studies, a researcher with expertise in school education should be included; 5) A support committee should be organized as an external part of the study team.

Relationship between children's intelligence and their emotional/behavioral problems and social competence: gender differences in first graders.

BACKGROUND: The present study examines gender differences in the correlations between intelligence and developmental problems as well as social competence in first graders. METHODS: Ninety parent-child dyads participated in this study. The children comprised 7-year-olds recruited from the first grade of an elementary school. All the children were administered the Wechsler Intelligence Scale for Children-Third Edition (WISC-III), Parent-child Interaction Rating Scale (IRS), and the parent report version of Strength and Difficulties Questionnaire (SDQ). RESULTS: The findings clarified that the processing speed of boys significantly correlated with their peer relationship. On the other hand, the emotional symptoms exhibited by girls had a more common association with their intellectual abilities. The correlations between parenting and intellectual abilities differed in boys and girls. CONCLUSIONS: Children's gender should be taken into account when assessing the diversity in their intellectual abilities and developmental problems. Moreover, parenting also influences the development of children in various ways.