Dear all,
Currently, I am doing a research project about serum sodium levels and falling. I am doing my analysis in R. I am performing the multiple imputation right now. I want to perform a survival analysis later, but therefore I need to specify the Nelson-Aalen estimator. My dataset is called DF1, the event indicator is Falls and the time variable is Time. The code that I use is as follows:
NAE <- nelsonaalen(data = DF1, statusvar = Falls, timevar = Time)
However, I get this error: Error in Surv(time, status) : Time variable is not numeric
If I do the following:
class(DF1$Time) [1] "numeric"
It shows that my variable is numeric. Can you help me with how I can solve this issue?
Thank you in advance.
Lisa