It’s often recommended that cases with excessive amounts of missing data should be eliminated from the analysis. Assuming that you’ve decided what constitutes “excessive” missing data, how can you easily identify cases that exceed this value? SPSS makes it easy, if you know the trick. Here it is. Write syntax as follows:
COUNT CMISS = var1 var2 var3….varx (MISSING).
(except use the names of variables you’re interested in in place of var1 … varx). This will add a variable to your data file called CMISS which lists for each case how many values are missing in the series of variables var1 to varx. You then easily identify cases with more missing values than you’re willing to tolerate.