Hi,
I have performed proc logistic for un-stratified and age-stratified analyses, but strangle, my un-stratified Odds Ratio is way smaller than the individual stratified OR (ODDS ratio) values. It should be close to an average of the other 2 stratified OR values.
Here are the ORs.
The red coloed value is no where close to the average of the 2 stratified ORs.
| CKD Stage III/IV- Overall | 1.74 (1.67-1.82) |
| Age <65 | 2.02 (1.82 -2.25) |
| Age >=65 | 1.95 (1.86 - 2.03) |
| CKD Stage V/ESRD Overall | 3.79 (3.62- 3.96) |
| Age <65 | 4.41 (4.04- 4.81) |
| Age >=65 | 3.52 (3.34- 3.70) |
I checked and rechecked my coding and program but don't find anything wrong with it. I am not able to figure out why the overall OR is not close to the average of the other 2 ORs.
The program code are as below. The red colored variable is variable of interest. It has 3 levels, 0,1 and 2 and 0 is reference category, 1= CKD stage III/IV and 2- CKD stage 5. Each program gives 2 Odds ratio values for this variable; 1 compared to 0 and 2 compared to 0. Interestingly the OR values for CKD stage V look correct and the overall OR seems to be an average of the other 2 stratified ORs.
Any suggestions, advice would be greatly appreciated.
proc logistic data =
class female (ref= first) renalicd9_3 (ref=first) dm_all_comorbid htn_c dyslipidemia aids alcohol ANEMDEF arth race1(ref=first)
ZIPINC_QRTL(ref=first) hosp_location h_contrl(ref=first) hosp_teach bldloss chf chrnlung coag depress drug hypothy liver lymph
lytes mets neuro obese para perivasc psych pulmcirc tumor ulcer valve wghtloss cararrhythmia sepsis pneumonia/param=ref;
model anyproc1_15_1= age female los dm_all_comorbid TOTAL_DISC htn_c dyslipidemia aids alcohol ANEMDEF arth race1 ZIPINC_QRTL hosp_location
h_contrl hosp_teach bldloss chf chrnlung coag depress drug hypothy liver lymph lytes mets neuro obese para perivasc
psych pulmcirc tumor ulcer valve wghtloss cararrhythmia sepsis pneumonia renalicd9_3;
where stemi=1;
weight discwt;
title 'Logi Reg anyproc vs renalicd9 in MI patients with RACE +income for stemi';
run;
quit;
proc logistic data =library.Nismicathckdmiss_pcilos30_1 descending;
class female (ref= first) renalicd9_3 (ref=first) dm_all_comorbid htn_c dyslipidemia aids alcohol ANEMDEF arth race1(ref=first)
ZIPINC_QRTL(ref=first) hosp_location h_contrl(ref=first) hosp_teach bldloss chf chrnlung coag depress drug hypothy liver lymph
lytes mets neuro obese para perivasc psych pulmcirc tumor ulcer valve wghtloss cararrhythmia sepsis pneumonia/param=ref;
model anyproc1_15_1= female los dm_all_comorbid TOTAL_DISC htn_c dyslipidemia aids alcohol ANEMDEF arth race1 ZIPINC_QRTL hosp_location
h_contrl hosp_teach bldloss chf chrnlung coag depress drug hypothy liver lymph lytes mets neuro obese para perivasc
psych pulmcirc tumor ulcer valve wghtloss cararrhythmia sepsis pneumonia renalicd9_3;
where stemi=1 and agecat3=1;
weight discwt;
title 'Logi Reg anyproc vs renalicd9 in MI patients with RACE +income for stemi <65';
run;
quit;
proc logistic data =library.Nismicathckdmiss_pcilos30_1 descending;
class female (ref= first) renalicd9_3 (ref=first) dm_all_comorbid htn_c dyslipidemia aids alcohol ANEMDEF arth race1(ref=first)
ZIPINC_QRTL(ref=first) hosp_location h_contrl(ref=first) hosp_teach bldloss chf chrnlung coag depress drug hypothy liver lymph
lytes mets neuro obese para perivasc psych pulmcirc tumor ulcer valve wghtloss cararrhythmia sepsis pneumonia /param=ref;
model anyproc1_15_1= female los dm_all_comorbid TOTAL_DISC htn_c dyslipidemia aids alcohol ANEMDEF arth race1 ZIPINC_QRTL hosp_location
h_contrl hosp_teach bldloss chf chrnlung coag depress drug hypothy liver lymph lytes mets neuro obese para perivasc
psych pulmcirc tumor ulcer valve wghtloss cararrhythmia sepsis pneumonia renalicd9_3;
where stemi=1 and agecat3=2;
weight discwt;
title 'Logi Reg anyproc vs renalicd9 in MI patients with RACE +income for stemi >=65';
run;
quit;
