help with multiple imputation

[Kyra]

Hi!

I am working with a dataset with missing values for few observations.

I would like to do multiple imputation for them.

The variables are below:

BMI_1_year          Frequency Missing = 199

BMI_6_mon                    Frequency Missing = 122

Post_op_BMI_4_weeks          Frequency Missing = 127

Pre_op_BMI                         Frequency Missing = 177

Please let me know sas code to do it.

I have attached a part of my dataset.

Thanks,

[Kyra]

I am not able to attach my dataset. sorry. It says "The contents of the attachment doesn't match its file type."

[SAS_Rob]

You will need to decide which methodology you want to use specifically.  This link in the MI documentation will help you to decide:

https://go.documentation.sas.com/?docsetId=statug&docsetVersion=14.3&docsetTarget=statug_mi_details0...

Once you decide between MCMC vs FS/Monotone then there are good examples of the coding in the documentation as well.

https://go.documentation.sas.com/?docsetId=statug&docsetVersion=14.3&docsetTarget=statug_mi_examples...

[Kyra]

Thank you very much for the reply. I will go through the paper.

[Kyra]

How do i know if the missing pattern is monotone or arbitrary?

I looked into the examples provided in document but it is not clear.

Thanks.

[SAS_Rob]

MI provides a table in the output with the missing data pattern. Since you have all continuous variables you could use the MCMC method and the NIMPUTE=0 option to see only the missing data pattern.

[Kyra]

I used the following code:

proc mi data=red.sleeve1  nimpute=0  ;
   mcmc chain=multiple displayinit initial=em(itprint);
   var BMI_1_year       BMI_6_mon      Post_op_BMI_4_weeks     Pre_op_BMI ;
run;

The sas output i got is attached. How do i interpret this. Thanks.