Hello.   I am trying to sum 5 columns to get a total score for each participant (row); however, I don't want SAS to sum rows with missing data, but I also don't want to delete those participants as I have data for them on a different variable.   So far I have tried    data want; set have; sum_W1= sum(var1, var2, var3, var4, var5); run;   however this sums across the row even if I'm missing data in 4 out of the 5 columns.    For instance  var 1  var 2 var 3  var 4   var 5 .            .            3        .             .   This is giving me a total score of 3 but I want it to read .    Thanks for any help!  ... View more