Solved – How to compare regression coefficients in the same simple regression model

regression

I think someone can help me to solve this problem. I scanned 40 samples in order to obtain two parameters: BMD and TBS. I have performed a regression analysis in order to study the relationship between BMD (dependent variable) and TBS (indipendent variable).
After that I have damaged the samples with a compression (mechanical) test. Then I rescanned the samples in order to measure BMD and TBS. I have performed a t-test and I have verified that BMD and TBS change after the damage.
Now I want to perform a second regression analysis between BMD and TBS and compare the regression coefficients of this second regression analysis with the first one.
How can I do it? Is there a particular test for this case?

Best Answer

Have a look at what's discussed here: Testing equality of coefficients from two different regressions.

Though you actually describe a setup with paired samples here, which might give you alternative options.