Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
From | "Joseph Coveney" <stajc2@gmail.com> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | st: Re: RE: Re: Dunnett's P-value and negative binomial regression |
Date | Tue, 21 Jan 2014 21:36:54 +0900 |
Garry Anderson wrote: By the way, I manually set k to 4 rather than e(df_m) because I had some covariates, as well as the 5 treatment levels. -------------------------------------------------------------------------------- If you're doing a lot of these, then you could probably automate it a bit. Something like that below, which you'd run immediately after your -nbreg- estimation command. It assumes by default that your control group is 1.varname after using factor variables in -nbreg-, which I think is usually the case. It's pretty rudimentary, but you could get elaborate and have the command query the ereturn macros left behind by the estimation command and set the inverse link, make it rclass and have it dump everything into return a matrix and so on. Joseph Coveney program define eformdunnettci version 13.1 syntax varname(numeric), [control(integer 1) level(integer `c(level)')] quietly levelsof `varlist' if e(sample), local(levels) local levels : list levels - control local comparison_tally : list sizeof levels tempname Dunnett scalar define `Dunnett' = invdunnettprob(`comparison_tally', /// 1e6, `level' / 100) local varname : variable label `varlist' if "`varname'" == "" local varname `varlist' tempname HalfCI foreach i of local levels { display in smcl as text _newline(1) /// "`varname' `i' versus `varname' `control'" quietly lincom `i'.`varlist' scalar define `HalfCI' = r(se) * `Dunnett' display in smcl as text "Estimate = " exp(r(estimate)) display in smcl as text "Asymp. `level'% LCL = " /// as result exp(r(estimate) - `HalfCI') display in smcl as text "Asymp. `level'% UCL = " /// as result exp(r(estimate) + `HalfCI') } end * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/