st: Quick question of using -concord- to investigate proportional errors

[cecilia sam <samcecilia2010@gmail.com>]

Hi all,

I am new to statistics and Stata, and need help for using -concord- in
Stata 11.0 for Windows.

I am comparing two datasets derived from 2 different methods. I
natural log transformed both datasets on the original scale, and typed
-concord y x, loa(regline)-. The output provides the slope of the
regression line, and a p-value listed besides the Pearson r (I
attached a part of the Stata output and attached below). Is this the
p-value that indicate the signficance of the slope of the regression
line?  In this case, does the p-value <0.05 mean that there are
statitically signficant proportional errors ?


Pearson's r =  0.271  Pr(r = 0) = 0.002  C_b = rho_c/r =  0.966

Reduced major axis:   Slope =     1.301   Intercept =    -2.727

Difference = y - x

        Difference                 95% Limits Of Agreement

   Average     Std Dev.             (Bland & Altman, 1986)

---------------------------------------------------------------

     0.010       0.333                 -0.643      0.663

Correlation between difference and mean = 0.266

Thank you very much.
Regards,
Cecilia

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/