Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: equivalence tests


From   Joseph Coveney <[email protected]>
To   Statalist <[email protected]>
Subject   Re: st: equivalence tests
Date   Wed, 11 Jul 2007 01:04:58 +0900

Ronan Conroy wrote:

Has anyone cooked up a tost (two one-sided tests) ado?

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

Isn't it something like that below?  (Also, "test1:" and "test2:" reported
by -equim- are the TOST.)

Joseph Coveney

clear
set more off
sysuse auto
ttest price, by(foreign) level(90)
local delta = 0.2 * r(mu_1) // Domestic is "reference group"
* Option 1:  By inspection, declare therapeutic equivalence if
* 90% CI is contained within the interval -delta to +delta
display in smcl as result `delta'
* Option 2:  Schuirmann's Two One-sided Tests (TOST);
* reject at alpha = 10% (5%, one-sided)
* (Note: TOST is operationally equivalent to Option 1 above)
local difference = r(mu_1) - r(mu_2) // mu_reference - mu_test
display in smcl as result 2 * ttail(r(df_t), (`delta'-`difference')/r(se))
display in smcl as result 2 * ttail(r(df_t), (`delta' + `difference')/r(se))
exit

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index