ELN/fisackson wrote:
> There exists a technique known as Orthogonal Distance Regression (aka
> Deming regression) to establish if a linear relationhsip exists between
> two variables when both are subject to error. A few statistics packages
> even calculate it. I wonder if there exists a similar technique to
> calculate a correlation coefficient bewteen two such variables, of if the
> old Pearson correlation coefficient does not assume inerrancy in one
> variable and is thus a sound measure. ID the Pearson moment is
> unsatisfactory and someone knows of an algorithm or equations from which
> one might calculate a suitable measure, I'd be grateful to hear from you.
If you have, or can obtain, replicates on each of the variables, then there
are approaches to correct correlation coefficients for random errors in both
sets of measurements. Application depends upon your study design and the
assumptions your are willing to make.
A reference for confidence interval estimation for corrected correlations and
references to earlier work is:
Rosner & Willet, Am J Epidemiol 1988;127:377-86.
--
Michael
