[R] concordance correlation coefficient using R

Marc Schwartz marc_schwartz at comcast.net
Sun Dec 7 17:37:58 CET 2008

on 12/07/2008 09:23 AM paul murima wrote:
> Hi.
> I have data which i would want to assess the degree of  agreement
> between two assays, e.g., to evaluate reproducibility or for
> inter-rater reliability. I have used the  Pearson product-moment
> correlation coefficient. It looks good ranginging between 0.90 to
> 0.998. Though this looks good. I am told the Concordance correlation
> coefficient will give a better picture of how reproducible the assay
> is.
> Does any one know how to run such a test using R? If so can you kindly
> provide the code, and bit of explanations to spruce it up?
> Thank you
> Paul

Look at the epi.ccc function in the epiR CRAN package. More information


You might also want to review Martin Bland's page pertaining to the
design and analysis of measurement agreement studies:



Marc Schwartz

More information about the R-help mailing list