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Weighted least-squares approach for comparing correlated kappa.

Publication ,  Journal Article
Barnhart, HX; Williamson, JM
Published in: Biometrics
December 2002

In the medical sciences, studies are often designed to assess the agreement between different raters or different instruments. The kappa coefficient is a popular index of agreement for binary and categorical ratings. Here we focus on testing for the equality of two dependent kappa coefficients. We use the weighted least-squares (WLS) approach of Koch et al. (1977, Biometrics 33, 133-158) to take into account the correlation between the estimated kappa statistics. We demonstrate how the SAS PROC CATMOD can be used to test for the equality of dependent Cohen's kappa coefficients and dependent intraclass kappa coefficients with nominal categorical ratings. We also test for the equality of dependent Cohen's kappa and dependent weighted kappa with ordinal ratings. The major advantage of the WLS approach is that it allows the data analyst a way of testing dependent kappa with popular SAS software. The WLS approach can handle any number of categories. Analyses of three biomedical studies are used for illustration.

Duke Scholars

Published In

Biometrics

DOI

ISSN

0006-341X

Publication Date

December 2002

Volume

58

Issue

4

Start / End Page

1012 / 1019

Location

England

Related Subject Headings

  • Uterine Cervical Diseases
  • Statistics & Probability
  • Reproducibility of Results
  • Observer Variation
  • Least-Squares Analysis
  • Humans
  • Female
  • Eye Diseases
  • Biometry
  • Bias
 

Citation

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Barnhart, H. X., & Williamson, J. M. (2002). Weighted least-squares approach for comparing correlated kappa. Biometrics, 58(4), 1012–1019. https://doi.org/10.1111/j.0006-341x.2002.01012.x
Barnhart, Huiman X., and John M. Williamson. “Weighted least-squares approach for comparing correlated kappa.Biometrics 58, no. 4 (December 2002): 1012–19. https://doi.org/10.1111/j.0006-341x.2002.01012.x.
Barnhart HX, Williamson JM. Weighted least-squares approach for comparing correlated kappa. Biometrics. 2002 Dec;58(4):1012–9.
Barnhart, Huiman X., and John M. Williamson. “Weighted least-squares approach for comparing correlated kappa.Biometrics, vol. 58, no. 4, Dec. 2002, pp. 1012–19. Pubmed, doi:10.1111/j.0006-341x.2002.01012.x.
Barnhart HX, Williamson JM. Weighted least-squares approach for comparing correlated kappa. Biometrics. 2002 Dec;58(4):1012–1019.
Journal cover image

Published In

Biometrics

DOI

ISSN

0006-341X

Publication Date

December 2002

Volume

58

Issue

4

Start / End Page

1012 / 1019

Location

England

Related Subject Headings

  • Uterine Cervical Diseases
  • Statistics & Probability
  • Reproducibility of Results
  • Observer Variation
  • Least-Squares Analysis
  • Humans
  • Female
  • Eye Diseases
  • Biometry
  • Bias