[R] Comparison of demographics between 2 study samples

[Jim Lemon]

On Wed, 2008-08-13 at 19:14 -0700, Mark Home wrote:
> Dear All:
> 
> I have a clinical study where I would like to compare the demographic information for 2 samples in a study.  The demographics include both categorical and continuous variables.  I would like to be able to say whether the demographics are significantly different or not.
> 
> The majority of papers that I have read use multiple techniques to achieve this (e.g., t-test for the continuous variables and either Fischer exact or Chi-square for categorical).  I wonder whether this might lead to spurious differences due to multiple significance tests.  Is there a better way to do this?
> 
Hi Mark,
Most of these comparisons are uncorrected, as the aim is to demonstrate
that the samples come from the same population. Therefore, you aren't
worried about making a Type I error, but ignoring a sampling difference
that might bias your results.

Jim