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iuri_leite
Fluorite | Level 6

Dear All,

We are analyzing data from a cohort of participants with a high risk of HIV infection. At this moment, our focus is on sexually transmitted disease infection. Given that patients in our cohort may have more than one sexually transmitted disease, we are considering using a frailty model.

We are currently thinking of using the COX Regression model, but I would like to check if the data structure I am creating is correct.  

The structure of our database would incorporate time-dependent variables.

Here we have the data for three participants. The observation of the participant 1 (ID=1) is censored at the first visit, then he experiences the event at the second visit, and does not return. The second participant experiences several events while the third one is censored at all visits.

ID  TSTART TSTOP STATUS 

1         0           91         0

1        91        187        1

2         0          115       0

2         115       210      1

2         210       321      0

2        321        430      1

2        430        542      1

3        0            122      0

3        122       312       0

3       312       431        0

 

The other issue I wanted to address is how to decide on the distribution of the random parameter associated with frailty. Is there a specific test for this?

Thank you..

Best regards,

Iuri leite

 

1 REPLY 1
sbxkoenk
SAS Super FREQ

Hello,

I am not an expert in frailty models (for sure not in practice), but here's some info.

BR, Koen

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