Pooled Odds Ratio

[Recep]

Hello all,

I was wondering what would be the best procedure to use to calculate pooled odds ratio (OR)? I have a raw data for 6 separate studies where a certain drug (and placebo) were tested for a health condition. I can calculate the ORs for the individual studies but I am having a hard time to calculate the pooled OR when I put all the record level information into one file. Below is the descriptive stats for those studies:

Study	Placebo	Patient_died	Count	Percent
STUDY 1	No	No	597	21.5601
STUDY 1	No	Yes	78	2.8169
STUDY 1	Yes	No	1851	66.8472
STUDY 1	Yes	Yes	243	8.7757
STUDY 2	No	No	1245	48.0139
STUDY 2	No	Yes	155	5.9776
STUDY 2	Yes	No	1086	41.882
STUDY 2	Yes	Yes	107	4.1265
STUDY 3	No	No	768	55.3314
STUDY 3	No	Yes	92	6.6282
STUDY 3	Yes	No	477	34.366
STUDY 3	Yes	Yes	51	3.6744
STUDY 4	No	No	238	19.2246
STUDY 4	No	Yes	46	3.7157
STUDY 4	Yes	No	790	63.8126
STUDY 4	Yes	Yes	164	13.2472
STUDY 5	No	No	590	65.1934
STUDY 5	No	Yes	118	13.0387
STUDY 5	Yes	No	171	18.895
STUDY 5	Yes	Yes	26	2.8729
STUDY 6	No	No	1345	33.0629
STUDY 6	No	Yes	202	4.9656
STUDY 6	Yes	No	2239	55.0393
STUDY 6	Yes	Yes	282	6.9322

I know that the pooled OR can be calculated both from the individual study ORs (which are below) and from the pooled data set where all the raw data for those studies is under one file.

	OR	LCL	UCL
STUDY 1	1.0048	0.7661	1.3179
STUDY 2	0.7914	0.6105	1.0258
STUDY 3	0.8925	0.6222	1.2802
STUDY 4	1.0741	0.7511	1.5359
STUDY 5	0.7602	0.4811	1.2012
STUDY 6	0.8386	0.6915	1.017

I was wondering if someone can help to calculate the pooled OR either from the individual study ORs or from the pooled data set.

For reference below is the SAS code I use that does NOT yield the pooled OR.

proc freq data=master;
by study;
tables placebo*patient_died/nopercent norow nocol out=master_pooled;
run;

proc freq data=master_pooled;
weight count;
tables patient_died*placebo/chisq relrisk;
run;

Thanks a lot in advance!

Recep

[Watts · Accepted solution]

proc freq data=have; 
tables study * placebo * patient_died / cmh;
weight count;
run;

The CMH option in the TABLES statement provides the overall/adjusted odds ratio for multiway (stratified) 2x2 tables. See the documentation section Adjusted Odds Ratio and Relative Risks .

[Recep]

Thanks a lot for very prompt and accurate response!