{smcl} {* 30sep2004}{...} {hline} help for {cmd:mijoin7}, {cmd:misplit7}{right:Patrick Royston} {hline} {title:Join or split multiple imputed datasets} {p 8 17 2} {c -(}{cmd:mijoin7} [{it:filestubname}] | {cmd:misplit7}{c )-} {cmd:,} {cmd:clear} [ {cmd:m(}{it:#}{cmd:)} {cmdab:imp:id(}{it:varname}{cmd:)} ] {title:Description} {p 4 4 2} {cmd:mijoin7} converts datasets prepared by Carlin's {help miset} routine to {help mvis} format, for analysis by {help micombine7}. The component datasets are stacked (joined vertically). If {it:filestubname} is specified then the program will look for files called {it:filestubname}{cmd:1.dta}, {it:filestubname}{cmd:2.dta},..., {it:filestubname}{cmd:m.dta} where {cmd:m} is determined by the {cmd:m()} option. {p 4 4 2} {cmd:misplit7} converts a dataset prepared by {help mvis} to {help miset} format, for analysis by {help mifit} and other utilities. You should {cmd:use} the dataset first. {p 4 4 2} The operations performed by {cmd:mijoin7} and {cmd:misplit7} are reciprocal. {title:Options} {p 4 8 2} {cmd:clear} is not optional and confirms that you are willing to replace the data in memory. {p 4 8 2} {cmd:impid(}{it:varname}{cmd:)} sets the name of the variable identifying the imputations to {it:varname} (default is {cmd:_j}). {cmd:mijoin7} creates {it:varname} whereas {cmd:misplit7} expects it to exist already. {p 4 8 2} {cmd:m(}{it:#}{cmd:)} sets the number of imputed datasets to be {it:#}. {title:Remarks} {p 4 4 2} After {cmd:mijoin7} has been executed, the data are ready for immediate use by {cmd:micombine7}. However, to save the data permanently you would need to issue a {help save} command. {p 4 4 2} After {cmd:misplit7} has been executed, the data are ready for immediate use by Carlin's routines. However, to save the data permanently you would need to issue a {help misave} command followed by {help miset} on the next use. {title:Examples} {p 4 8 2}{cmd:. mvis y x1 x2 x3 using imp, m(3)}{p_end} {p 4 8 2}{cmd:. use imp, clear}{p_end} {p 4 8 2}{cmd:. misplit7, clear}{p_end} {p 4 8 2}{cmd:. mifit regress y x1 x2 x3} {p 4 8 2}{cmd:. miset using imp, clear mimps(5)}{p_end} {p 4 8 2}{cmd:. mijoin7, clear}{p_end} {p 4 8 2}{cmd:. micombine7 regress y x1 x2 x3} {p 4 8 2}{cmd:. mijoin7 imp, clear m(5)}{p_end} {p 4 8 2}{cmd:. save imp_mvis}{p_end} {p 4 8 2}{cmd:. micombine7 regress y x1 x2 x3} {title:Author} {p 4 4 2} Patrick Royston, MRC Clinical Trials Unit, London. patrick.royston@ctu.mrc.ac.uk {title:References} {p 4 4 2} Carlin, J. B., N. Li, P. Greenwood, and C. Coffey. 2003. Tools for analyzing multiple imputed datasets. The Stata Journal 3 (3): 226-244. {title:Also see} {p 4 13 2} Online: help for {help mvis7}, {help micombine77}