[R] Nelson-Aalen Estimator in R: Error Message

[A.C. van der Burgh]

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


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