[R] concordance correlation coefficient using R

[Marc Schwartz]

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
here:

 http://bm2.genes.nig.ac.jp/RGM2/R_current/library/epiR/man/epi.ccc.html

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

 http://www-users.york.ac.uk/~mb55/meas/meas.htm


HTH,

Marc Schwartz