Dear R-users,

I use the survsplit function in the survival package to change my data into
counting-process format

and the transformed format is as follow:

(a)
start  stop   event   DP  age ....
0      5         0        1       20
5     10        0        1       20
10    25       1        1       20


looking at the above three entries  that belong to the same person, if an
event happen at time 5,  won't the person  actually enter the risk set twice
since there is another entry that start at time 5 and Cox proportional
hazard model "won't know" that it actually belong to the same person.

Shouldn't it be like this?

(b)
start  stop   event   DP  age ....
0      5         0        1       20
6    10         0        1       20
11   25        1        1       20

or  the R-function coxph has already take this into account when calculating
its risk set although  I believe (a) is actually the correct one.
Your advice is greatly appreciated!

regards,
sing yee

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