Obtaining a pooled estimate with proc freq

[bretthouston]

Hello, 

I recently performed a propensity analysis using stratification (n=7 strata). To estimate the treatment effect across all stratas, I would like to pool this estimate using proc freq. I've tried the following code:

proc psmatch data=HipF region=cs(extend=0);

class TXAstatus sex CS1 CS2 CS3 year2014 year2015 anesth2 anesth3 surg2 surg3;

psmodel TXAstatus (Treated='1') = age sex CS1 CS2 CS3 preopHb anesth2 anesth3 surg2 surg3 year2014 year2015;

strata nstrata=7 key=none;

assess lps var=(age sex CS1 CS2 CS3 preopHb anesth2 anesth3 surg2 surg3 year2014 year2015) / 

plots = (stddiff) stddev=pooled;

output out(obs=region)=TXAstrat10;

run;

proc freq data=TXAstrat;

tables Tx*TXAstatus / cmh;

exact mcnem;

by _STRATA_;

run;

Despite specifying 'CMH', this seems to generate stratum-specific ORs and RRs. Is there an option that I'm missing here? 

Thanks in advance,

Brett

[SAS_Rob · Accepted solution]

You should remove the BY statement and place the _STRATA_ variable on the TABLES statement.

proc freq data=TXAstrat;

tables _strata_*Tx*TXAstatus / cmh;

exact mcnem;

run;

[bretthouston]

Thank-you, this is perfect. Much appreciated!