<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">
  <docDscr>
    <citation>
      <titlStmt>
        <titl xml:lang="sv">NewTwin – genetiska, sociala och miljömässiga faktorers påverkan på hälsa och beteende – en studie från
Svenska Tvillingregistret</titl>
        <parTitl xml:lang="en">NewTwin – Genetic, Social and Environmental Factors Impact on Health and Behavior - A Study from the Swedish Twin Registry</parTitl>
        <IDNo agency="SND">2024-486-1</IDNo>
      </titlStmt>
      <prodStmt>
        <producer xml:lang="en" abbr="SND">Swedish National Data Service</producer>
        <producer xml:lang="sv" abbr="SND">Svensk nationell datatjänst</producer>
      </prodStmt>
    </citation>
  </docDscr>
  <stdyDscr>
    <citation>
      <titlStmt>
        <titl xml:lang="sv">NewTwin – genetiska, sociala och miljömässiga faktorers påverkan på hälsa och beteende – en studie från
Svenska Tvillingregistret</titl>
        <parTitl xml:lang="en">NewTwin – Genetic, Social and Environmental Factors Impact on Health and Behavior - A Study from the Swedish Twin Registry</parTitl>
        <IDNo agency="SND">2024-486-1</IDNo>
      </titlStmt>
      <rspStmt>
        <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">2021-00180_VR, 2017-00641_VR</grantNo>
        <grantNo xml:lang="sv" agency="Vetenskapsrådet">2021-00180_VR, 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="2025-02-11" />
      </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="2025-02-11" />
      </verStmt>
    </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/D005823">Genetics</keyword>
        <keyword xml:lang="sv" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D005823">Genetik</keyword>
        <keyword xml:lang="en" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D005838">Genotype</keyword>
        <keyword xml:lang="sv" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D005838">Genotyp</keyword>
        <keyword xml:lang="en" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D014427">Twins</keyword>
        <keyword xml:lang="sv" vocab="MeSH" vocabURI="http://id.nlm.nih.gov/mesh/D014427">Tvillingar</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>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Economics.IncomePropertyAndInvestmentSaving">Income, property and investment/saving</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Economics.IncomePropertyAndInvestmentSaving">Inkomster, egendom och investeringar/sparande</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health">HEALTH</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health">HÄLSA</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.MedicationAndTreatment">Medication and treatment</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.MedicationAndTreatment">Medicinering och behandlingar</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.ReproductiveHealth">Reproductive health</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.ReproductiveHealth">Fortplantningshälsa</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.SpecificDiseasesDisordersAndMedicalConditions">Specific diseases, disorders and medical conditions</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.SpecificDiseasesDisordersAndMedicalConditions">Specifika sjukdomar, störningar och medicinska tillstånd</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.GeneralHealthAndWellbeing">General health and well-being</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.GeneralHealthAndWellbeing">Allmän hälsa och välbefinnande</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=LabourAndEmployment.Employment">Employment</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=LabourAndEmployment.Employment">Sysselsättning</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=LabourAndEmployment.Unemployment">Unemployment</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=LabourAndEmployment.Unemployment">Arbetslöshet</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=SocialStratificationAndGroupings.Children">Children</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=SocialStratificationAndGroupings.Children">Barn</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=SocietyAndCulture.SocialConditionsAndIndicators">Social conditions and indicators</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=SocietyAndCulture.SocialConditionsAndIndicators">Sociala förhållanden och indikatorer</topcClas>
        <topcClas xml:lang="en" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.DrugAbuseAlcoholAndSmoking">Drug abuse, alcohol and smoking</topcClas>
        <topcClas xml:lang="sv" vocab="CESSDA Topic Classification" vocabURI="https://vocabularies.cessda.eu/vocabulary/TopicClassification?code=Health.DrugAbuseAlcoholAndSmoking">Drogmissbruk, alkohol och rökning</topcClas>
      </subject>
      <abstract xml:lang="en" contentType="abstract">This ongoing twin study, initiated in 2021, focuses on all twins born in Sweden. Parents are invited to complete an online questionnaire when their twins are approximately nine months old. The questionnaire includes areas such as pregnancy, neonatal care, screen time and parental health habits. Additionally, saliva samples are collected to determine the twins' zygosity and genotyping. The genotype data is used in genetic association studies to explore diseases, health-related traits and behaviors.

Question Areas:

Parents' education, income and occupation
Fertility treatment
Parents’ health 
Parents’ smoking and alcohol habits (current and during pregnancy)
Pregnancy from the mother's perspective
Pregnancy from the twins' perspective
Birth weight and length
Neonatal care
Breastfeeding
Vaccinations
Twin development 
Sleep habits of the twins
Zygosity, twin similarities and differences
Family screen time and screen use</abstract>
      <abstract xml:lang="sv" contentType="abstract">En pågående tvillingstudie sen 2021 riktad till alla tvillingar födda i Sverige. Föräldrar bjuds in att fylla i en webenkät när deras tvillingar är cirka nio månader gamla.  Enkäten omfattar frågeområden om graviditet, neonatal vård, skärmtid och föräldrars hälsovanor. Dessutom samlas salivprov in för att fastställa tvillingarnas zygositet och för genotypning. Genotypdata används i genetiska associationsstudier för att undersöka sjukdomar, hälsorelaterade egenskaper och beteenden.

Frågeområden:
Föräldrarnas utbildning, inkomst och yrke
Fertilitetsbehandling
Föräldrars hälsa 
Föräldrars rök- och alkoholvanor, nuvarande och under graviditeten
Graviditet, moderns perspektiv
Graviditet, tvillingarnas perspektiv
Födelsevikt och längd
Neonatalvård
Amning
Vaccinationer
BVC och utveckling 
Tvillingarnas sömnvanor
Zygositet
Familjens användning av skärm</abstract>
      <sumDscr>
        <collDate xml:lang="en" date="2021-11-01" event="single">2021-11-01</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>
        <anlyUnit xml:lang="sv" unit="Familj">Familj<concept vocab="DDI Analysis Unit" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/AnalysisUnit/2.1.3?languageVersion=sv-2.1.3">Familj</concept></anlyUnit>
        <universe xml:lang="en">Twins born in Sweden since January 1, 2021, onwards, at approximately 9 months of age.</universe>
        <universe xml:lang="sv">Tvillingar födda i Sverige sedan 1 januari 2021, vid ca 9 månaders ålder.</universe>
        <dataKind xml:lang="en">Numeric</dataKind>
        <dataKind xml:lang="en">Text</dataKind>
      </sumDscr>
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    <method>
      <dataColl>
        <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>
        <timeMeth xml:lang="en">Longitudinal: Cohort/Event-based<concept vocab="DDI Time Method" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/TimeMethod/1.2.3?languageVersion=en-1.2.3">Longitudinal: Cohort/Event-based</concept></timeMeth>
        <timeMeth xml:lang="sv">Longitudinell: Kohort/Händelsebaserad<concept vocab="DDI Time Method" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/TimeMethod/1.2.3?languageVersion=sv-1.2.3">Longitudinell: Kohort/Händelsebaserad</concept></timeMeth>
        <sampProc xml:lang="en">Parents of twins born in Sweden, where both twins are alive, are invited to participate when the twins are 
between 7 and 10 months old. Twins are excluded if they have protected identity, have emigrated, or if their
parents have opted out of contact with the Swedish Twin Registry. Only complete twin pairs are invited.<concept vocab="DDI Sampling Procedure" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/SamplingProcedure/2.0.1?languageVersion=en-2.0.1">Parents of twins born in Sweden, where both twins are alive, are invited to participate when the twins are 
between 7 and 10 months old. Twins are excluded if they have protected identity, have emigrated, or if their
parents have opted out of contact with the Swedish Twin Registry. Only complete twin pairs are invited.</concept></sampProc>
        <sampProc xml:lang="sv">Föräldrar till tvillingar födda i Sverige, där båda tvillingarna är vid liv, bjuds in att delta i studien när tvillingarna är mellan 7 och 10 månader gamla. Tvillingar exkluderas om de har skyddad identitet, utvandrat eller om föräldrarna har avsagt sig kontakt med Svenska Tvillingregistet. Endast hela tvillingpar inkluderas i inbjudan.<concept vocab="DDI Sampling Procedure" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/SamplingProcedure/2.0.1?languageVersion=sv-2.0.1">Föräldrar till tvillingar födda i Sverige, där båda tvillingarna är vid liv, bjuds in att delta i studien när tvillingarna är mellan 7 och 10 månader gamla. Tvillingar exkluderas om de har skyddad identitet, utvandrat eller om föräldrarna har avsagt sig kontakt med Svenska Tvillingregistet. Endast hela tvillingpar inkluderas i inbjudan.</concept></sampProc>
        <sampProc xml:lang="en">Total universe/Complete enumeration<concept vocab="DDI Sampling Procedure" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/SamplingProcedure/2.0.1?languageVersion=en-2.0.1">Total universe/Complete enumeration</concept></sampProc>
        <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>
        <collMode xml:lang="en">An invitation to a web survey is sent to all parents of Swedish-born twins aged 7–10 months, followed by two reminders. The parents are also asked whether they wish to provide saliva samples from the twins. If they agree, they receive a saliva kit by mail, which they then send to KI Biobank along with a consent form.<concept vocab="DDI Mode of Collection" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/ModeOfCollection/5.0.0?languageVersion=en-5.0.0">An invitation to a web survey is sent to all parents of Swedish-born twins aged 7–10 months, followed by two reminders. The parents are also asked whether they wish to provide saliva samples from the twins. If they agree, they receive a saliva kit by mail, which they then send to KI Biobank along with a consent form.</concept></collMode>
        <collMode xml:lang="sv">En inbjudan till en webenkät skickas ut till alla föräldrar med svenskfödda tvilingar i åldern 7-10 månader, följt av två påminnelser. Föräldrarna får också ta ställning till om de vill lämna salivprov från tvillingarna. I så fall får de ett salivkit hemskickat som de sedan skickar in till Biobanken tillsammans med ett samtycke.<concept vocab="DDI Mode of Collection" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/ModeOfCollection/5.0.0?languageVersion=sv-5.0.0">En inbjudan till en webenkät skickas ut till alla föräldrar med svenskfödda tvilingar i åldern 7-10 månader, följt av två påminnelser. Föräldrarna får också ta ställning till om de vill lämna salivprov från tvillingarna. I så fall får de ett salivkit hemskickat som de sedan skickar in till Biobanken tillsammans med ett samtycke.</concept></collMode>
        <collMode xml:lang="en">Self-administered questionnaire<concept vocab="DDI Mode of Collection" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/ModeOfCollection/5.0.0?languageVersion=en-5.0.0">Self-administered questionnaire</concept></collMode>
        <collMode xml:lang="sv">Självadministrerat frågeformulär<concept vocab="DDI Mode of Collection" vocabURI="https://vocabularies.cessda.eu/v2/vocabularies/ModeOfCollection/5.0.0?languageVersion=sv-5.0.0">Självadministrerat frågeformulär</concept></collMode>
      </dataColl>
    </method>
    <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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