Program concord implements L. I. Lin's concordance correlation coefficient (Lin, 1989), as well as the limits-of-agreement procedure (Bland and Altman, 1986). Recently, Lin (2000) issued an erratum reporting a number of typographical errors in his seminal 1989 paper. Further, changes in Stata Version 7 required modification of concord. This note reports the effect of the errors and provides a corrected and updated program.
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JenkinsS. P.1999. sg105: Creation of bivariate random lognormal variables. Stata Technical Bulletin48: 18–19. In Stata Technical Bulletin Reprints, vol. 8, 260–261. College Station, TX: Stata Press.
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LinL. I.1989. A concordance correlation coefficient to evaluate reproducibility. Biometrics45: 255–268.
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LinL. I.-K.2000. A note on the concordance correlation coefficient. Biometrics56: 324–325.
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SteichenT. J., and CoxN.J.1998a. sg84: Concordance correlation coefficient. Stata Technical Bulletin43: 35–39. In Stata Technical Bulletin Reprints, vol. 8, 137–143. College Station, TX: Stata Press.
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SteichenT. J.1998b. sg84.1: Concordance correlation coefficient, revisited. Stata Technical Bulletin45: 21–23. In Stata Technical Bulletin Reprints, vol. 8, 143–145. College Station, TX: Stata Press.
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SteichenT. J.2000. sg84.2: Concordance correlation coefficient, update for Stata 6. Stata Technical Bulletin54: 25–26. In Stata Technical Bulletin Reprints, vol. 9, 169–170. College Station, TX: Stata Press.
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SteichenT. J.2001. sg84.3: Concordance correlation coefficient, minor corrections. Stata Technical Bulletin58: 9. In Stata Technical Bulletin Reprints, vol. 10, 137. College Station, TX: Stata Press.
