Re: st: stored p-value of sts test

[Phil Clayton <philclayton@internode.on.net>]

After performing a log-rank test, -sts test- returns the chi-squared and degrees of freedom as r(chi2) and r(df) - see -help sts test-. There is no r(p) but you can easily calculate the p-value using r(chi2), r(p) and Stata's chi2tail() function.

sts test `x', logrank
if chi2tail(r(df), r(chi2)) < 0.05 {
	sts graph, by(`x') tmax(60)
	graph save `x', replace
}

Phil

On 21/01/2012, at 5:08 AM, Steve Nakoneshny wrote:

> Dear Statalisters,
> 
> I am performing some exploratory analyses in an stsetted dataset using Stata 11.2 for Mac.
> 
> As part of a loop, I coded the following:
> 
> -- start code --
> 
> sts test `x', logrank
> sts graph, by(`x') tmax(60)
> graph save `x', replace
> 
> -- end code --
> 
> My local `x' comprises 18 variables, so the loop generates more graphs than I actually want to save. Looking at the help, I see that -sts graph- accepts -if- statements. What I would like to do is only graph (and save) where -sts test- is statistically significant (p<0.05). According to -help-, -sts test- doesn't save the p-value in r().
> 
> What I would like to know is whether or not the p-value is stored somewhere else (if at all) or if there is an alternate workaround I can implement.
> 
> 
> Thanks,
> Steve
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