help misum
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Title

     misum -- Summary statistics in MI dataset

Syntax

        misum [varlist] [if] [in] [weight] [, m(numlist) detail format(%fmt)
                                            matrix(name)]


            by is allowed

            aweights, fweights and iweights are allowed.  However, iweights are
            not allowed with detail. See summarize


Description

    misum calculates summary statistics in MI datasets. Results from 
    summarize are combined, applying Rubin's combination rules.


Options

        +---------+
    ----+ Options +----------------------------------------------------------

    m(numlist) combines results from imputed datasets numlist.  Numbers of
        imputed datasets must be given in ascending order.

    detail calculates additional statistics and returns them in r(). See 
        summarize.

    format(%fmt) displays results in specified format.

    matrix(name) returns the result matrix in r(name).


Remarks

    misum calls summarize for each imputed dataset. The returned results are
    added up and divided by M, where M is the number of imputed datasets. The
    standard deviation is calculated as the square root of the variance.

    misum requires the data to be flong style (also see mi set, mi convert).
    The data may also be in ice format (Royston 2005).


Example

    Use with mi (Stata 11 or higher)

        . sysuse auto

        . mi set flong

        . mi register imputed rep78

        . mi impute regress rep78 = price mpg weight ,add(5)

        . misum rep78 price mpg

    Use with ice (Stata 9.2 or higher)

        . sysuse auto ,clear

        . ice rep78 price mpg weight ,clear m(5) cmd(regress)

        . misum rep78 price mpg


Saved results

    misum calls summarize and saves any results returned for each variable.
    It therefore saves the following in r():

    Scalars
        r(varname_stat) (avarage) stat for varname returned by summarize

    Matrices
        r(name)         result matrix (matrix only)


Acknowledgments

    Sebastian Pink suggested downward compatibility with Stata 9.2 and data
    in ice format.

References

    Royston, P. (2005) Multiple imputation of missing values: update. Stata
    Journal 5 (2), 188-201.


Author

    Daniel Klein, University of Bamberg, klein.daniel.81.@gmail.com


Also see

    Online: mi, summarize

    if installed: ice