Question

I am trying to combine the odds ratios outputted from two models with different adjustments in SAS:

i.e:

ods output oddsratios=adjustedOR1(rename=(OddsRatioEst=OR1);
 proc logistic data=dataname; 
      model y= b d c a e; run;

ods output oddsratios=adjustedOR2 (rename=(OddsRatioEst=OR2);
 proc logistic data=dataname; 
      model y= b d c; run;

proc sort…..

data Oddsratios (keep=Effect OR1 OR2);
merge adjustedOR1 adjustedOR2; by effect; run;

Problem is that if I sort and merge by the Effect variable, I lose the order in which I put the explanatory variables in the model.

Is there anyway to assign an index to the variable according to the order I put it in the model, so that the final table will have the effect column in the order: b d c a e?

Thanks for your help

Answer 1

I suggest creating a new sequence variable in your “primary” dataset with the sort order you want. then re-sorting the merged result by that variable:

data adjustedOR1;
   set adjustedOR1;
   sortkey = _n_;
run;
proc sort data=adjustedOR1;
   by effect;
run;
proc sort data=adjustedOR2;
   by effect;
run;
data Oddsratios (keep=Effect OR1 OR2 sortkey);
   merge adjustedOR1 adjustedOR2; 
      by effect;
run;
proc sort data=Oddsratios;
  by sortkey;
run;

This would be a bit more generic than hard-coding the sort sequence as Keith suggests using PROC SQL (which also works by the way).

And thanks to Keith for providing a practical example!