<codeBook xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:schemaLocation="ddi:codebook:2_5 http://www.ddialliance.org/Specification/DDI-Codebook/2.5/XMLSchema/codebook.xsd" xmlns="ddi:codebook:2_5">
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    <citation>
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        <titl xml:lang="sv">CATSS9 - The Child and Adolescent Twin Study in Sweden (9 år, telefonintervju)</titl>
        <parTitl xml:lang="en">CATSS9 - The Child and Adolescent Twin Study in Sweden (9 years, telephone interview)</parTitl>
        <IDNo agency="SND">2024-492-1</IDNo>
      </titlStmt>
      <prodStmt>
        <producer xml:lang="en" abbr="SND">Swedish National Data Service</producer>
        <producer xml:lang="sv" abbr="SND">Svensk nationell datatjänst</producer>
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    <citation>
      <titlStmt>
        <titl xml:lang="sv">CATSS9 - The Child and Adolescent Twin Study in Sweden (9 år, telefonintervju)</titl>
        <parTitl xml:lang="en">CATSS9 - The Child and Adolescent Twin Study in Sweden (9 years, telephone interview)</parTitl>
        <IDNo agency="SND">2024-492-1</IDNo>
        <IDNo agency="DOI">10.1375/twin.14.6.495</IDNo>
      </titlStmt>
      <rspStmt>
        <AuthEnty xml:lang="en" affiliation="Department of Medical Epidemiology and Biostatistics, Karolinska Institutet">Lichtenstein, Paul</AuthEnty>
        <AuthEnty xml:lang="sv" affiliation="Institutionen för medicinsk epidemiologi och biostatistik, Karolinska Institutet">Lichtenstein, Paul</AuthEnty>
        <AuthEnty xml:lang="en" affiliation="Department of Medical Epidemiology and Biostatistics, Karolinska Institutet">Magnusson, Patrik</AuthEnty>
        <AuthEnty xml:lang="sv" affiliation="Institutionen för medicinsk epidemiologi och biostatistik, Karolinska Institutet">Magnusson, Patrik</AuthEnty>
      </rspStmt>
      <prodStmt>
        <grantNo xml:lang="en" agency="The Swedish Research Council">2017-00641_VR</grantNo>
        <grantNo xml:lang="sv" agency="Vetenskapsrådet">2017-00641_VR</grantNo>
      </prodStmt>
      <distStmt>
        <distrbtr xml:lang="en" abbr="SND" URI="https://snd.se">Swedish National Data Service</distrbtr>
        <distrbtr xml:lang="sv" abbr="SND" URI="https://snd.se">Svensk nationell datatjänst</distrbtr>
        <distDate xml:lang="en" date="2025-05-21" />
      </distStmt>
      <serStmt>
        <serName xml:lang="en" abbr="str">The Swedish Twin Registry</serName>
        <serInfo xml:lang="en">The Swedish Twin Registry collects, holds and distributes data about twins, for research projects with ethical permission.</serInfo>
        <serInfo xml:lang="sv">Svenska tvillingregistret samlar, håller och delar data om tvillingar till etikprövade forskningsprojekt</serInfo>
      </serStmt>
      <verStmt>
        <version elementVersion="1" elementVersionDate="2025-05-21" />
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    </citation>
    <stdyInfo>
      <subject>
        <keyword xml:lang="en" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D010641">Phenotype</keyword>
        <keyword xml:lang="sv" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D010641">Fenotyp</keyword>
        <keyword xml:lang="en" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D014429">Twins, Dizygotic</keyword>
        <keyword xml:lang="sv" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D014429">Tvåäggstvillingar</keyword>
        <keyword xml:lang="en" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D014430">Twins, Monozygotic</keyword>
        <keyword xml:lang="sv" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D014430">Enäggstvillingar</keyword>
        <keyword xml:lang="en" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D059647">Gene-Environment Interaction</keyword>
        <keyword xml:lang="sv" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D059647">Gen-miljöinteraktion</keyword>
      </subject>
      <abstract xml:lang="en" contentType="abstract">Overview
The Child and Adolescent Twin Study in Sweden (CATSS) is an ongoing longitudinal twin study that targets all twins born in Sweden since July 1, 1992 and living in Sweden at the study inquiries. Between 2004 and 2019, twin parents were interviewed about the children's somatic and psychological health and social environment in connection with their 9th birthday (CATSS9). As of 2020, the telephone interview has been replaced with a web survey (CATSS9W). At age 15 (CATSS15) and age 18 (CATSS18), twins and parents complete a web-based questionnaire that, in addition to assessments of somatic and mental health, includes measures of personality development and psychosocial adjustment. At the age of 24 (CATSS24), twins complete a web survey that focuses primarily on mental health.

Fundraising for CATSS9 started in 2004 and ended in 2019. Parents of all of Sweden's 9-year-old twins were invited to participate in a telephone interview regarding the twins' health and behavior. The interview captured various health problems such as asthma, allergies and diabetes as well as behaviors such as physical activity and social interaction. The number of participating twins is 34400, with a response rate of 69%.

In connection with the CATSS9 interview, the parents also received a request to provide DNA via saliva samples from the twins.  The saliva sample is used for zygosity determination and genotyping. The number of genotyped twins participating in CATSS9 is 21 500 (December 2024).

Question areas:
Administrative Information
Allergy, Asthma, Eczema
A-TAC - Autism - Tics, AD/HD and other Comorbidities inventory 
CPTI - Child Problematic Traits Inventory
Demographic Information
Drugs
LSC-R Life Stressor Checklist- Revised (trauma)
Physical Activity
PTSD - DSM-IV Criteria for Posttraumatic Stress Disorder (trauma)
SCARED - Screen for Child Anxiety Related Emotional Disorders
School Environment &amp; Support in School
SCM - Stattin Child Monitoring
Sicklist, somatic
SMFQ - Short Mood and Feelings Questionnaire (depression)
Spare Time Activities
Weight &amp; Height</abstract>
      <abstract xml:lang="sv" contentType="abstract">Översikt
The Child and Adolescent Twin Study in Sweden (CATSS) är en pågående longitudinell tvillingstudie som riktar sig till alla tvillingar födda i Sverige sedan 1 juli 1992 och boende i Sverige vid kontakttillfällena. Mellan 2004 och 2019 intervjuades tvillingföräldrar om barnens somatiska och psykiska hälsa och sociala miljö i samband med deras 9-årsdag (CATSS9). Från och med 2020 är telefonintervjun ersatt med en webbenkät (CATSS9W). Vid 15 (CATSS15) och 18 (CATSS18) års ålder, fyller tvillingar och föräldrar i en webenkät som, förutom bedömningar av somatisk och mental hälsa, inkluderar mått på personlighetsutveckling och psykosocial anpassning. Vid 24 års ålder (CATSS24) fyller endast tvillingar i en webenkät som främst fokuserar på mental hälsa.

Insamlingen för CATSS9 startade 2004 och avslutades 2019. Föräldrar till alla Sveriges 9-åriga tvillingar bjöds in till att delta i en telefonintverju rörande tvillingarnas hälsa och beteende. Intervjun fångade upp olika hälsoproblem såsom astma, allergier och diabetes samt beteenden som fysisk aktivitet och social interaktion. Antalet deltagande tvillingar är ca 34400, med en svarsfrekvens på 69%.

I samband med CATSS9-intervjun fick även föräldrarna en förfrågan om att lämna DNA via salivprov från tvillingarna.  Salivprovet används för zygositetsbestämning och genotypning. Antalet genotypade tvillingar som deltagit i CATSS9 är 21 500 (december 2024).

Frågeområden:
Administrativ information 
Allergi, astma, eksem
A-TAC - Autism-Tics, ADHD och andra komorbiditeter
CPTI - Inventering av problematiska egenskaper hos barn
Demografisk information
Fritidsaktiviteter
Fysisk aktivitet
LSC-R - Checklista för livsstressorer – Reviderad (trauma)
Läkemedel
PTSD - posttraumatiskt stressyndrom (trauma)
SCARED - Barnångestrelaterade känslomässiga störningar
SCM - Stattin Barn Monitorering 
Skolmiljö och stöd i skolan 
SMFQ - Humör och känslor, depression
Somatiska sjukdomar
Vikt och längd</abstract>
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        <collDate xml:lang="en" date="2004-10-01" event="start">2004-10-01</collDate>
        <collDate xml:lang="en" date="2020-06-30" event="end">2020-06-30</collDate>
        <nation xml:lang="en" abbr="SE">Sweden</nation>
        <nation xml:lang="sv" abbr="SE">Sverige</nation>
        <anlyUnit xml:lang="en" unit="Individual">Individual<concept vocab="DDI Analysis Unit" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/AnalysisUnit/2.1.3?languageVersion=en-2.1.3">Individual</concept></anlyUnit>
        <anlyUnit xml:lang="sv" unit="Individ">Individ<concept vocab="DDI Analysis Unit" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/AnalysisUnit/2.1.3?languageVersion=sv-2.1.3">Individ</concept></anlyUnit>
        <anlyUnit xml:lang="en" unit="Family">Family<concept vocab="DDI Analysis Unit" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/AnalysisUnit/2.1.3?languageVersion=en-2.1.3">Family</concept></anlyUnit>
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        <universe xml:lang="en">9-year-old twins born in Sweden between July 1, 1992, and December 31, 2010</universe>
        <universe xml:lang="sv">9-åriga tvillingar födda i Sverige mellan 1992-07-01 och 2010-12-31</universe>
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        <timeMeth xml:lang="en">Cross-section<concept vocab="DDI Time Method" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/TimeMethod/1.2.3?languageVersion=en-1.2.3">Cross-section</concept></timeMeth>
        <timeMeth xml:lang="sv">Tvärsnitt<concept vocab="DDI Time Method" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/TimeMethod/1.2.3?languageVersion=sv-1.2.3">Tvärsnitt</concept></timeMeth>
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        <sampProc xml:lang="en">All 9-year-old twins, both same-sex and opposite sex, born in Sweden between July 1, 1992, and December 31, 2010, as recorded in the Swedish Medical Birth Register and residing in Sweden at the time of invitation, were eligible for inclusion. Only complete twin pairs where invited to participate. Twins with protected identities, who have emigrated, or who were deceased were excluded.<concept vocab="DDI Sampling Procedure" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/SamplingProcedure/2.0.1?languageVersion=en-2.0.1">All 9-year-old twins, both same-sex and opposite sex, born in Sweden between July 1, 1992, and December 31, 2010, as recorded in the Swedish Medical Birth Register and residing in Sweden at the time of invitation, were eligible for inclusion. Only complete twin pairs where invited to participate. Twins with protected identities, who have emigrated, or who were deceased were excluded.</concept></sampProc>
        <sampProc xml:lang="sv">Alla, både sam- och olikkönade,  9-åriga tvillingar födda i Sverige mellan 1992-07-01 och 2010-12-31, enligt medicinska födelseregistret (Socialstyrelsen) och boende i Sverige vid inbjudningstillfället. Endast hela tvillingpar bjöds in. Tvillingar som har skyddad identitet, utvandrat eller avlidit exkluderades.<concept vocab="DDI Sampling Procedure" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/SamplingProcedure/2.0.1?languageVersion=sv-2.0.1">Alla, både sam- och olikkönade,  9-åriga tvillingar födda i Sverige mellan 1992-07-01 och 2010-12-31, enligt medicinska födelseregistret (Socialstyrelsen) och boende i Sverige vid inbjudningstillfället. Endast hela tvillingpar bjöds in. Tvillingar som har skyddad identitet, utvandrat eller avlidit exkluderades.</concept></sampProc>
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        <sampProc xml:lang="sv">Hela populationen/total räkning<concept vocab="DDI Sampling Procedure" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/SamplingProcedure/2.0.1?languageVersion=sv-2.0.1">Hela populationen/total räkning</concept></sampProc>
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        <collMode xml:lang="sv">Telefonintervju<concept vocab="DDI Mode of Collection" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/ModeOfCollection/5.0.0?languageVersion=sv-5.0.0">Telefonintervju</concept></collMode>
        <collMode xml:lang="en">Telephone interview<concept vocab="DDI Mode of Collection" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/ModeOfCollection/5.0.0?languageVersion=en-5.0.0">Telephone interview</concept></collMode>
        <collMode xml:lang="sv">Telefonintervju<concept vocab="DDI Mode of Collection" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/ModeOfCollection/5.0.0?languageVersion=sv-5.0.0">Telefonintervju</concept></collMode>
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    <dataAccs>
      <useStmt>
        <restrctn xml:lang="en">Access to data through an external actor. Access to data is restricted.</restrctn>
        <restrctn xml:lang="sv">Åtkomst till data via extern aktör. Tillgång till data är begränsad.</restrctn>
        <conditions elementVersion="info:eu-repo-Access-Terms vocabulary">restrictedAccess</conditions>
      </useStmt>
    </dataAccs>
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      <relPubl>
        <citation>
          <titlStmt>
            <titl xml:lang="sv">Anckarsäter H, Lundström S, Kollberg L, Kerekes N, Palm C, Carlström E, Långström N, Magnusson PK, Halldner L, Bölte S, Gillberg C, Gumpert C, Råstam M, Lichtenstein P. The Child and Adolescent Twin Study in Sweden (CATSS).
Twin Res Hum Genet. 2011 Dec;14(6):495-508.</titl>
            <parTitl xml:lang="en">Anckarsäter H, Lundström S, Kollberg L, Kerekes N, Palm C, Carlström E, Långström N, Magnusson PK, Halldner L, Bölte S, Gillberg C, Gumpert C, Råstam M, Lichtenstein P. The Child and Adolescent Twin Study in Sweden (CATSS).
Twin Res Hum Genet. 2011 Dec;14(6):495-508.</parTitl>
            <IDNo agency="DOI">10.1375/twin.14.6.495</IDNo>
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            <distDate date="2011">2011</distDate>
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