Re: st: mi impute chained troubleshooting

[Stas Kolenikov <skolenik@gmail.com>]

First of all, we'd all be better off if you showed the output and
reported the error message verbatim. You may have had a syntax error,
for instance, rather than a statistical difficulty.

In terms of modifying the equations, you can specify -omit( tc_all )-
option to remove that variable from your equations, although you would
still get it imputed since it appeared in -mi impute- statement. If it
is an arithmetic sum of hdl and ldl, then you should -mi register
passive tc_all- and -mi passive : generate tc_all = hdl_all +
ldl_all-.

-- Stas Kolenikov, PhD, PStat (ASA, SSC)
-- Senior Survey Statistician, Abt SRBI
-- Opinions stated in this email are mine only, and do not reflect the
position of my employer
-- http://stas.kolenikov.name



On Tue, Jul 16, 2013 at 2:59 PM, Jacob McDermott <jpmcd87@gmail.com> wrote:
> Hello Statalist,
>
> The following mi impute chained command (unsurprisingly) returns an error
> mi impute chained (ologit) educacion (regress) height hba1c_all glucose_all
> hdl_all ldl_all triglyc_all crp_all tc_all  (logit) obesidad tension corazon
> diabetes smoke1 exercise1, add(5) by(female)
>
> The issue rising from collinearity due to the inclusion of tc(total
> cholesterol) along with ldl and hdl (major components of total cholesterol)
> Note: tc_all ldl_all and hdl_all are continuous variables with roughly 10%
> missing values
>
> If I remove tc_all from the imputation command (or if I remove either ldl or
> hdl) everything runs just fine, but I do not get imputed values for tc_all.
>
> Is there anything I can do to get imputed values for tc_all?
>
> What I have been trying is running the above imputation command twice (once
> excluding tc_all and again excluding ldl_all), and then merging in tc_all
> imputed values from the second run into the first imputed dataset. My only
> real justification for this is that ldl and tc are highly correlated and the
> resulting imputed datasets appear to be very similar . Do you think this
> procedure is at all legitimate? Do you know of any alternatives?
>
> Thanks for your help,
> Jacob
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