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Re: st: mi with imputed data sets only?
From
Steven Samuels <[email protected]>
To
[email protected]
Subject
Re: st: mi with imputed data sets only?
Date
Fri, 22 Jul 2011 15:57:33 -0400
--
In fact, exactly this technique is described at the end of: http://www.ats.ucla.edu/stat/stata/faq/no_m_eq_0.htm . "How can I use multiply imputed data where original data is not included?"
Also, for Stata Versions< 11, -mim- (available at SSC) works with many estimation commands and doesn't require the original data.
Steve
[email protected]
On Jul 20, 2011, at 9:19 AM, Steven Samuels wrote:
Follow-up:
It was easy to recreate the original (m = 0) data set. To do so, I calculated for each respondent the SD over imputations of each of the possibly imputed variables. The SD would be zero for values that had not been imputed and >0 for imputed observations.
I took one imputed set, and set each possibly imputed variable to missing if the SD of that variable over imputations was >0, changed the imputation indicator to 0 and appended it to the original data. -foreach- loops over the list of possibly imputed variables helped a lot.
Interestingly, the SD analysis found about 80 observations that are erroneously coded as having no imputations.
Anyone who would like to see the code for these analyses is welcome to write to me privately.
Steve
[email protected]
On Jul 19, 2011, at 9:11 AM, Steven Samuels wrote:
The US National Health and Examination Survey (NHANES) distributes multiply imputed data that consist of five imputation data sets. These are The 1999-2004 Dual Energy X-ray Absorptiometry (DXA) Multiple Imputation Data Files (http://www.cdc.gov/nchs/nhanes/dxx/dxa.htm). I cannot use Stata's -mi import- commands, because theserequire the original (m = 0) data.
I'm going to try to recreate the m = 0 data from the supplied imputation indicators. But before I do, I'd like to know: Is it possible to use -mi estimate- with only the imputed data sets? If so, how?
Thanks,
Steve
[email protected]
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