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      <Title language="en">Covariate adjustment, factorial designs and clustered data in diagnostic accuracy studies</Title>
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        <PersonNames>
          <Lastname>Weber</Lastname>
          <LastnameHeading>Weber</LastnameHeading>
          <Firstname>Philipp</Firstname>
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          <Affiliation>Institut f&#252;r Medizinische Biometrie und Epidemiologie, Universit&#228;tsklinikum Hamburg-Eppendorf, Hamburg, Germany</Affiliation>
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        <PersonNames>
          <Lastname>Vogel</Lastname>
          <LastnameHeading>Vogel</LastnameHeading>
          <Firstname>Frederike</Firstname>
          <Initials>F</Initials>
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          <Affiliation>Institut f&#252;r Medizinische Biometrie und Epidemiologie, Universit&#228;tsklinikum Hamburg-Eppendorf, Hamburg, Germany</Affiliation>
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          <Lastname>Konietschke</Lastname>
          <LastnameHeading>Konietschke</LastnameHeading>
          <Firstname>Frank</Firstname>
          <Initials>F</Initials>
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        <Address>
          <Affiliation>Charit&#233; - Universit&#228;tsmedizin Berlin, Berlin, Germany</Affiliation>
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          <Lastname>Zapf</Lastname>
          <LastnameHeading>Zapf</LastnameHeading>
          <Firstname>Antonia</Firstname>
          <Initials>A</Initials>
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        <Address>
          <Affiliation>Institut f&#252;r Medizinische Biometrie und Epidemiologie, Universit&#228;tsklinikum Hamburg-Eppendorf, Hamburg, Germany</Affiliation>
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          <Corporatename>German Medical Science GMS Publishing House</Corporatename>
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        <Address>D&#252;sseldorf</Address>
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    <SubjectGroup>
      <SubjectheadingDDB>610</SubjectheadingDDB>
      <Keyword language="en">diagnostic accuracy study</Keyword>
      <Keyword language="en">regression</Keyword>
      <Keyword language="en">clustered data</Keyword>
      <Keyword language="en">factorial designs</Keyword>
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      <DatePublished>20251103</DatePublished>
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    <Language>engl</Language>
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      <AltText language="en">This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License.</AltText>
      <AltText language="de">Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung).</AltText>
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      <Meeting>
        <MeetingId>M0631</MeetingId>
        <MeetingSequence>082</MeetingSequence>
        <MeetingCorporation>Deutsche Gesellschaft f&#252;r Medizinische Informatik, Biometrie und Epidemiologie</MeetingCorporation>
        <MeetingName>70. Jahrestagung der Deutschen Gesellschaft f&#252;r Medizinische Informatik, Biometrie und Epidemiologie e. V. (GMDS)</MeetingName>
        <MeetingTitle></MeetingTitle>
        <MeetingSession>V: Medical Biometry 2: Analysemethoden</MeetingSession>
        <MeetingCity>Jena</MeetingCity>
        <MeetingDate>
          <DateFrom>20250907</DateFrom>
          <DateTo>20250911</DateTo>
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      <MainHeadline>Text</MainHeadline><Pgraph><Mark1>Introduction:</Mark1> The accuracy of diagnostic tests is commonly evaluated by estimating the area under the receiver operating characteristic curve (AUC), as well as sensitivity and specificity at given diagnostic cut-offs.</Pgraph><Pgraph><Mark1>Challenges:</Mark1> However, many diagnostic trials use factorial designs. For example, different combinations of readers and methods may be used to diagnose a patient. Furthermore, diagnostic studies may generate clustered data by repeated measurements over time or several lesions, for example different brain regions. Dependencies between a person&#39;s observations must be taken into account in the analysis in order to prevent variance deflation. Lange <TextLink reference="1"></TextLink> developed a nonparametric mathematical framework to deal with both of these design aspects, and Lange and Brunner generalized the approach from the AUC to sensitivity and specificity <TextLink reference="2"></TextLink>.</Pgraph><Pgraph>Additionally, it may be of interest to adjust the estimation procedure of the above mentioned accuracy measures for covariates. For example, it may be the case that age, weight or height influence the diagnostic accuracy of a test. Zapf <TextLink reference="3"></TextLink> proposed a nonparametric methodological approach to adjust the AUC for such covariates, while also allowing for factorial designs, but not yet for clustered data.</Pgraph><Pgraph><Mark1>Conclusion:</Mark1> In this talk we present a new, unified method that enables covariate adjustment of the AUC, sensitivity and specificity in studies with factorial designs and clustered data. We will show the properties of the approach using simulated data and illustrate the approach with an example study.</Pgraph><Pgraph>The authors declare that they have no competing interests.</Pgraph><Pgraph>The authors declare that an ethics committee vote is not required.</Pgraph><Pgraph>The contribution has already been published: <TextLink reference="4"></TextLink></Pgraph></TextBlock>
    <References linked="yes">
      <Reference refNo="1">
        <RefAuthor>Lange K</RefAuthor>
        <RefTitle></RefTitle>
        <RefYear>2011</RefYear>
        <RefBookTitle>Nichtparametrische analyse diagnostischer G&#252;tema&#223;e bei Clusterdaten &#91;Dissertation&#93;</RefBookTitle>
        <RefPage></RefPage>
        <RefTotal>Lange K. Nichtparametrische analyse diagnostischer G&#252;tema&#223;e bei Clusterdaten &#91;Dissertation&#93;. 2011. DOI: 10.53846&#47;goediss-3538</RefTotal>
        <RefLink>https:&#47;&#47;doi.org&#47;10.53846&#47;goediss-3538</RefLink>
      </Reference>
      <Reference refNo="3">
        <RefAuthor>Zapf A</RefAuthor>
        <RefTitle></RefTitle>
        <RefYear>2009</RefYear>
        <RefBookTitle>Multivariates nichtparametrisches Behrens-Fisher-problem MIT Kovariablen &#91;Dissertation&#93;</RefBookTitle>
        <RefPage></RefPage>
        <RefTotal>Zapf A. Multivariates nichtparametrisches Behrens-Fisher-problem MIT Kovariablen &#91;Dissertation&#93;. 2009. DOI: 10.53846&#47;goediss-2488</RefTotal>
        <RefLink>https:&#47;&#47;doi.org&#47;10.53846&#47;goediss-2488</RefLink>
      </Reference>
      <Reference refNo="2">
        <RefAuthor>Lange K</RefAuthor>
        <RefAuthor>Brunner E</RefAuthor>
        <RefTitle>Sensitivity, specificity and ROC-curves in multiple reader diagnostic trials&#8212;a unified, nonparametric approach</RefTitle>
        <RefYear>2012</RefYear>
        <RefJournal>Statistical Methodology</RefJournal>
        <RefPage>490&#8211;500</RefPage>
        <RefTotal>Lange K, Brunner E. Sensitivity, specificity and ROC-curves in multiple reader diagnostic trials&#8212;a unified, nonparametric approach. Statistical Methodology. 2012;9(4):490&#8211;500. DOI: 10.1016&#47;j.stamet.2011.12.002</RefTotal>
        <RefLink>http:&#47;&#47;dx.doi.org&#47;10.1016&#47;j.stamet.2011.12.002</RefLink>
      </Reference>
      <Reference refNo="4">
        <RefAuthor>Weber P</RefAuthor>
        <RefAuthor>Kramer K</RefAuthor>
        <RefAuthor>Zapf A</RefAuthor>
        <RefTitle>Covariate adjustment, factorial designs and clustered data in diagnostic accuracy studies</RefTitle>
        <RefYear></RefYear>
        <RefBookTitle>70th Biometric Colloquium; 2024 Feb 28 &#8211; Mar 01; L&#252;beck, Germany</RefBookTitle>
        <RefPage></RefPage>
        <RefTotal>Weber P, Kramer K, Zapf A. Covariate adjustment, factorial designs and clustered data in diagnostic accuracy studies. In: 70th Biometric Colloquium; 2024 Feb 28 &#8211; Mar 01; L&#252;beck, Germany.</RefTotal>
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