proc phreg hazard ration levels list for categorical variables and choose reference category

MFraga — Fri, 19 Oct 2018 18:37:03 GMT

Hello,

I want to have in the output for a Cox regression (the table with the results for the estimates for maximum likelihood analysis) the list showing the results for each level of the independent variable "independent_v1" or "independent_v2".

My dataset is like this:

data have;

input

id time1 event1 weight independent_v1 independent_v2;

datalines;

1 0 0 0.8 0 1

1 1 0 0.8 0 1

1 2 0 0.8 0 0

1 3 0 0.8 0 0

1 4 0 0.8 0 1

15 0 0.8 0 1

1 6 0 0.8 0 1

1 7 0 0.8 0 1

1 8 0 0.8 0 2

1 9 0 0.8 0 2

1 10 0 0.8 0 2

1 11 0 0.8 0 2

1 12 0 0.8 0 2

1 13 0 0.8 0 2

2 0 0 1.1 1 0

2 1 1 1.1 1 0

2 2 . 1.1 1 0

3 0 0 1.01 2 1

3 1 0 1.01 2 1

3 2 1 1.01 2 1

3 3 . 1.01 2 1

4 0 1 0.98 2 1

4 1 . 0.98 2 1

4 2 . 0.98 2 1

4 3 . 0.98 2 1

4 4 . 0.98 2 1

5 0 0 1.13 3 0

6 0 0 1.05 3 0

6 1 0 1.05 3 1

6 2 0 1.05 3 1

6 3 0 1.05 3 1

6 4 0 1.05 3 1

6 5 1 1.05 3 1

6 6 . 1.05 3 1

6 7 . 1.05 1 1

6 8 . 1.05 1 1

7 0 0 0.89 0 3

7 1 0 0.89 0 3

7 2 0 0.89 0 3

7 3 0 0.89 0 3

7 4 0 0.89 0 3

7 5 0 0.89 0 3

7 6 0 0.89 0 3

7 7 0 0.89 0 3

7 8 1 0.89 0 1

7 9 . 0.89 0 1

7 10 . 0.89 0 1

8 0 0 1.1 1 0

8 1 0 1.1 1 1

8 2 0 1.1 1 1

8 3 . 1.1 1 2

8 4 . 1.1 1 2

;

run;

When I code I have the regression results list, but I would like to know how to change the reference category for each independent variable.

My coding:

proc phreg data=have;

class independent_v1 independent_v2;

id id;

model time1*event1(0) = independent_v1 independent_v2;

weight weight;

run;

So SAS automatically chooses to omit one level as the reference category for each independent variable. For example, How I could change that so I choose the reference category 1 for "independent_v1" and 3 for "independent_v2", ?

Thanks for the help!

Re: proc phreg hazard ration levels list for categorical variables and choose reference category

ballardw — Fri, 19 Oct 2018 18:42:29 GMT

You can add a REF= option to each class variable and specify either the level or Ref=First (for the lowest value)

class independent_v1 (ref='category 1') independent_v2 (ref='category 3');

You don't mention which value might be category 1 or 3. the value would the formatted value for the variable concerned and value of interest.

Re: proc phreg hazard ration levels list for categorical variables and choose reference category

MFraga — Fri, 19 Oct 2018 18:50:19 GMT

It works! Thanks!

topic proc phreg hazard ration levels list for categorical variables and choose reference category in New SAS User

proc phreg hazard ration levels list for categorical variables and choose reference category

Re: proc phreg hazard ration levels list for categorical variables and choose reference category

Re: proc phreg hazard ration levels list for categorical variables and choose reference category