I have looked at the previous posts, and have not been able to make sense of it.
My data set is made of binary variables for a list of patient, disease, health characteristics (i.e. sex, diabetes, cardiac disease). Some are continuous variables (i.e. operation time in minutes) and others are categorical (i.e. tumour location).
The outcome was any complications post-op.
There is a total of 24 variables and 141 lines of data.
Variable | Number of outputs available | Number of outputs missing |
1. Sex | 141 | 0 |
2. Thickness, categorical | 141 | 0 |
3. Histology, subtype | 141 | 0 |
4. Mitosis, binary | 68 | 73 |
5. Ulceration | 78 | 63 |
6. LVI | 69 | 72 |
7. Regression | 63 | 78 |
8. Smoker | 116 | 25 |
9. Diabetes | 141 | 0 |
10. Cardiac disease | 141 | 0 |
11. Hypothyroidism | 141 | 0 |
12. Staff/surgeon | 141 | 0 |
13. Presentation | 141 | 0 |
14. Indication | 141 | 0 |
15. Dissection type | 139 | 2 |
16. OP time | 133 | 8 |
17. Blood loss | 91 | 50 |
18. Number of drains left | 141 | 0 |
19. Duration of immobility | 79 | 62 |
20. Duration of post-op AB use | 80 | 61 |
21. Total hospital stay | 80 | 61 |
22. Total LN | 140 | 1 |
23. Total positive LN | 141 | 0 |
24. ER revisit | 141 | 0 |
I've done correlation analyses; most had a RH0 of ~0.3-0.4. I couldn't perform VIF/tolerance tests, oddly.
So to test the model, I did both univariate and multivariate analyses. An example of my code...
Where sex = 1 is male, where comp = 1 is any complication.
proc logisitic data = groin descending;
class sex (ref = '0')/param = ref;
model comp = sex/clodds = wald orpvalue; run;
And with each variable, the output states, "All Observations have the same response. No statistics are computed".
Your list of variables and those counts does not show COMP or anything that looks like the outcome "complications post-op".
You need to look closely at that variable and possibly in combination with your SEX variable to see if different levels of sex had any variation in Comp.
Such as
Proc freq data=groin;
tables sex*comp/list;
run;
If there are no differences in COMP (when not missing) within levels of Sex then that is the reason.
What does a PROC FREQ on `comp` tell you?
Thank you and good catch, it seemed like the code didn't run through for comp. And it was all 0's.
Your list of variables and those counts does not show COMP or anything that looks like the outcome "complications post-op".
You need to look closely at that variable and possibly in combination with your SEX variable to see if different levels of sex had any variation in Comp.
Such as
Proc freq data=groin;
tables sex*comp/list;
run;
If there are no differences in COMP (when not missing) within levels of Sex then that is the reason.
Ah, I see thank you!
Registration is now open for SAS Innovate 2025 , our biggest and most exciting global event of the year! Join us in Orlando, FL, May 6-9.
Sign up by Dec. 31 to get the 2024 rate of just $495.
Register now!
Learn how use the CAT functions in SAS to join values from multiple variables into a single value.
Find more tutorials on the SAS Users YouTube channel.
Ready to level-up your skills? Choose your own adventure.