topic Re: How to bootstrap/re-sample repeated measures data by subject ID in SAS? in New SAS User

How to bootstrap/re-sample repeated measures data by subject ID in SAS?

mahim — Wed, 20 Mar 2019 22:58:36 GMT

I am trying to:

1. Sample repeated measures data based on subject IDs for cross validation of a GENMOD model,

2. Bootstrap a dataset because of a highly skewed outcome measure recorded in an unbalanced long format (e.g a patient may may have 5 observations for t1, 0 for t2, 3 for t3, and so on, where 't's are time points).

Is there a well explained macro/guide available for resampling or bootstrapping repeated measures data based on subject IDs? I want to resample by ID so that all observations per subject are captured by the procedure in the train/test sets. Please do correct me if I am wrong; I believe simple random sampling by replacement, which may be done using proc surveyselect, would not be an efficient method for repeated measures data. How can I modify proc surveyselect to incorporate subject IDs?

Re: How to bootstrap/re-sample repeated measures data by subject ID in SAS?

PGStats — Thu, 21 Mar 2019 03:42:29 GMT

@Rick_SAS has posted many great entries on Bootstrap. Look here

https://blogs.sas.com/content/?s=bootstrap

To make the subject ID the (re-)sampling unit, go for cluster sampling, where the subject is the cluster.

Re: How to bootstrap/re-sample repeated measures data by subject ID in SAS?

fbaumer — Mon, 20 Apr 2020 19:14:08 GMT

Hi - I have this exact same question. I've been looking through the recommended link and have not found a clear answer in the documentation. Did you ever find a way to do this? I have done a year of masters' level statistics so do rely on very specific instructions if I try one of these models (rather than extrapolating from related things like proc mixed).

Thank you!