6 Questions
What is the required format for structuring data with time-varying covariates in the Cox PH model?
Start-stop time format
How many time variables are required to record the beginning and end of time intervals for time-varying covariates?
2
When should the time when a covariate changes value be recorded?
As the beginning of a new interval
Which function in the survival package helps to get data in the required start-stop time format for time-varying covariates?
tmerge()
In the jasal dataset, what is considered as a time-varying covariate?
$transplant$
What does the 'status' variable record in the Cox PH model for single event data?
The event status as the end at each interval
This quiz covers the concept of time-varying covariates in the Cox Proportional Hazards model. It discusses the structured start-stop time format required for accommodating time-varying covariates and the use of time intervals and event status variable.
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