Creating a new variable in longitudinal data with similar cells based on other variable

[desireatem]

I have been struggling with one sas coding from encounter level to patient level. Please help.

So my data is like:

ID	dx_encounter level
1	1
1	0
1	0
1	1
2	0
2	0
2	0
3	1
3	0
3	0

I want to create the variable "dx_patient level" where if each patient ID received any "1" from "dx_encounter level", then "dx_patient level" should be 1. Otherwise it's 0.

The data I want is : 

ID	dx_encounter level	dx_patient level
1	1	1
1	0	1
1	0	1
1	1	1
2	0	0
2	0	0
2	0	0
3	1	1
3	0	1
3	0	1

 Thank you!

[Reeza · Accepted solution]

Some options:
Find the maximum and merge it in.
Use SQL to join and merge in the maximum.

Since 1 is always first in your examples, use RETAIN on first value and carry forward.

https://github.com/statgeek/SAS-Tutorials/blob/master/add_average_value_to_dataset.sas

Retain tutorial:
https://sascrunch.com/retain-statement/