The Swedish Twin Registry
The Swedish Registry was established in 1961 and is a research resource maintained at Karolinska Institutet. The registry includes an old cohort, comprised of 10,945 pairs of like-sexed twins born 1886 through 1925, a middle cohort comprised of approximately 50,000 pairs of like- and unlike sexed twins born 1926 through 1967, and a young cohort of approximately 45,000 pairs born since 1967. Questionnaire data has been collected from members of the old cohort in 1961, 1963, 1967, and 1970, and from like-sexed members (born 1926-1958) of the middle cohort in 1973. The questionnaire data include items about health, health-related behaviors, personality, physical activity, eating habits, and environmental stressors. All twins in the older two cohorts (45,000 individuals) have recently been contacted in a screening of major diseases, and a web-based contact with twins born 1959-1985 will soon be started. The twin registry is matched regularly to three national registries: the DAFA-SPAR address registry, the cancer registry, and the cause of death registry. In addition, the registry has been linked to a psychiatric and an infarct registry. There is substantial national and international research activity associated with the registry in the form of separate projects that cover a range of methodologies such as genetic epidemiology, behavior genetics, and cancer epidemiology. Applications to use data from the registry are handled by a steering committee.