Swedish Twin Registry - Birth Cohorts and Studies
In the STR dataportal you can search for metadata included in our cohorts and studies as well as create and download your own variable list. On this page you can find information about our studies grouped by cohorts and comprises questionnaires, PDF format files (Swedish only, when applicable), as well as areas of study, variables, codes and excel format files.
Please note that all files are password protected. To obtain the password contact the Swedish Twin Registry by sending an email to str-research@meb.ki.se.
You can find more information about our birth cohorts and studies on the Swedish National Data Service (SND).
Birth Cohorts and Studies
Questionnaire administrated in 1961
Questionnaire administrated in 1963
Questionnaire administrated in 1967
Questionnaire administrated in 1970
Questionnaire administrated in 1973
SALT (Screening Across the Lifespan Twin) administrated 1998–2002
TwinGene (Pair of twins from the SALT-study) administrated 2004–2008
SALTY (Screening Across the Lifespan Twin Young) administrated 2009–2010
- SALTY man questionnaire (Swedish only)
- SALTY woman questionnaire (Swedish only)
- SALTY area of study, questionnaire, codes (Swedish only)
- SALTY GWAS
Birth (Birth weight and risk of adult disease in offspring: etiologic determinants -29-58) data collected from birth journals
STAGE (Swedish Twin Studies of adults: Genes and Environment) administrated 2004–2006
STAGE ONE (Swedish Twin Studies of adults: Genes and Environment) follow-up of STAGE
YATSS - Young Adult Twin Study in Sweden
In 2013, researchers conducted the Young Adult Twin Study in Sweden (YATSS) to explore the influence of genetic and environmental factors on health and behavior. The study focused on young adult twins born between 1985 and 1992, aiming to understand how these factors contribute to various diseases and conditions. The study included a comprehensive range of health-related topics, addressing:
- Gastrointestinal disorders
- Pulmonary diseases
- Asthma and allergies
- Arthritis
- Affective disorders and symptoms
- Eating disorders
- Fibromyalgia
- Chronic fatigue syndrome
- Women’s health issues
The participant pool consisted of monozygotic (identical) and dizygotic (fraternal) twins, including both same-sex and opposite-sex pairs. Out of 16,244 twins invited, 6,870 participated, providing a solid basis for analysis. Participants were asked to provide saliva samples for zygosity determination and genotyping. From this group, 4,000 twins who participated in the YATSS survey were successfully genotyped.
For more details visit YATSS - Young Adult Twin Study in Sweden | Swedish National Data Service
CATSS – The Child and Adolescent Twin Study in Sweden
The Child and Adolescent Twin Study in Sweden (CATSS) is a longitudinal research initiative on twins born in Sweden since July 1, 1992. This ongoing study examines the interplay of genetic and environmental factors on somatic and mental health, personality development, and psychosocial adaptation across critical developmental stages.
Study Overview
CATSS collects data at key life stages, involving both parents and twins:
- CATSS-9: Starting in 2004, parents of twins are interviewed or fill in a questionnaire when the twins turn 9 years old. Topics include:
- Somatic health
- Mental health
- Social environment
- CATSS-15 & CATSS-18: At ages 15 and 18, both twins and their parents complete detailed questionnaires. These assessments expand to include:
- Personality development
- Psychosocial adaptation
- CATSS-24: At 24 years old, twins participate in a web survey. This phase primarily focuses on mental health outcomes.
In summary
- Study Start: 2004
- Cohort: Twins born in Sweden since July 1, 1992
- Data Collection:
- Age 9: Parent interviews/questionnaire (CATSS-9)
- Age 15 and 18: Questionnaires for both twins and parents (CATSS-15 & CATSS-18)
- Age 24: Web survey for twins (CATSS-24)
For more details about CATSS15, visit CATSS15 - The Child and Adolescent Twin Study in Sweden (15 years) | Swedish National Data Service
Born 1886-1925: Questionnaire administrated in 1961, 1963, 1967, 1970.
Born 1886-1958: Q73, SALT, Twin Gene, SALTY, Birth
Born 1959-1985: STAGE administrated 2004–2006.
Born 1985-1992: YATSS administered 2013.
Born 1992-2010: CATSS: Telephone interview administrated 2004–2019.
Important to Consider
Our surveys and interviews often include conditional questions, known as "branching." To ensure correct use and analysis of the data, it is essential that you review the documents outlining the questionnaire and interview structures before working with the data. You can find these documents under each respective study. They are labeled with the words “questionnaire” or “interview” in the document name and are organized by birth cohort.”