Swedish Twin Registry

Summary

Strengths The Swedish Twin Registry, managed by the Karolinska Institute, is the largest of its kind and has become an invaluable resource for medical research. It has a fundamental role for research on health, social bias and living conditions. More information available at: http://online.wsj.com/article_email/SB10001424052970204707104578095351618032528-lMyQjAxMTAyMDAwOTEwNDkyWj.html?mod=wsj_valetleft_email

Type of data

Data Source
Registry

Type of Study
Survey same
Crosssection regular
Cohort study
Other: Historical studies of twin populations, bio-med data.

Data gathering method
Face-to-face
Registries
Self administered questionnaire
Other: Biomed samples.

Access to data

Conditions of access
Available for the scientific community primarily by downloaded files in various applications.

Type of available data (e.g. anonymised microdata, aggregated tables, etc.)
Types of requests for access include: 1. Aggregated summary tables or statistics from the STR. 2. Anonymised files of raw and/or transformed data from the STR. 3. Above data plus linkages to health registries. 4. Access to identifying information for further collection of new data.

Formats available
The data set is compatible to many applications such as Excel, SAS, SPSS, STATA, Text, etc.

Coverage

Coverage Years of collection, reference years, and sample sizes
The Swedish Registry was established in the 1960s to study how smoking affects our health. At the time, little was known about the dangers of smoking. There is, at present, information on approximately 85,000 twin pairs, both monozygotic and dizygotic. There are currently about 30 ongoing projects based on the Swedish twin registry. The studies cover a wide range of public health issues, among others a focus on dementia diseases, allergies, cancer and cardiovascular diseases.

First year of collection
Various cohorts 1886, 1926, 1959

Stratification if applicable
Varies for different subsets.

Base used for sampling

Geographical coverage and breakdowns
The whole country

Age range
No age restrictions (birth cohorts)

Statistical representativeness
Special group, please specify

Coverage of main and cross-cutting topics
At present, about 30 ongoing projects based on the twin registry cover a broad spectrum in public health. Some areas being investigated are ageing, dementia, allergies, cancer, and cardiovascular disease. Other projects are about the effects of gender differences on health and life situations. Ongoing projects About 70,000 twins in Sweden born before 1985 have recently responded to questionnaires or interviews. The twins answered questions about diseases they have/had and drugs they use. Now we are analysing the information. To estimate how genes or environment influence different diseases and behavior in childhood, we contact parents to all Swedish twins turning 9- or 12-years-old. More than 6,000 twins' parents have been contacted so far. We continue to interview new parents to the 9 year old. Another exiting project is Dementia in Swedish Twins (HARMONY). It concerns ageing and memory. The aim of this study is to investigate which factors affect our memory capacity and incidence of dementia.

Linkage

Standardisation
ICD

Possibility of linkage among databases
The Twin Registries are subject to rich inter-disciplinary collaborations with scientists both within and outside Sweden.

Data quality

Entry errors if applicable

Breaks
STR has been developed over several years, but the fundamental structure is the same as from start. No major breaks.

Consistency of terminology or coding used during collection
High consistency in terminology.

Governance

Contact information
Department of Medical Epidemiology and Biostatistics
Karolinska Institutet
PO Box 281
171 77 Stockholm Sweden Phone: +46 8 524 87418
Email: tvillingregistret(at)ki.se
Url: http://ki.se/ki/jsp/polopoly.jsp?d=9610&l=en

Timeliness, transparency
Depends on the character of data to be supplied.