Help with Kaplan-Meier Analysis

#1
Hello

We have done a retrospective study on the survival of fillings in teeth. The situation is as follows:

When the filling was lost: Coded as "1" and survival time was noted
When the filling is intact: Coded as "0"

I have a problem here.... There are some cases when the tooth as a whole was removed due to some other dental reasons (even when the filling was intact). How should I code them??? It's confusing me. Kindly help me please...


Regards
Vinay
 

Karabiner

TS Contributor
#2
For each tooth you record
a) the length of the observation period (until the terminal event
took place, or until the observation was terminated for other
reasons).
b) the outcome: 1=terminal event [here: filling was lost], 0=censored
(observation was terminated because of end of prescheduled observation
period, or because of other reasons like e.g. contact was lost, subject
died, later records were eaten by a dog etc.).

So in case of a tooth which has fallen out, its observation period
ended with that event, and the observation was censored, because
the observation was terminated befor the terminal event had happened.

With kind regards

K.