Description Usage Arguments Value Author(s) See Also Examples
Calculation of Efron's re-distribution to the right algorithm to obtain the Kaplan-Meier estimate.
1 |
time |
A numeric vector of event times. |
status |
The event status vector takes the value |
Calculations needed to
Thomas A. Gerds <tag@biostat.ku.dk>
prodlim
1 |
Kaplan-Meier estimate via re-distribution to the right algorithm:
Subject 1:
---------------------------
Survival before = 100%
No event until time = 0.35
Re-distribute mass 0.17 to remaining 5 subjects
Survival after = 100%
Subject 2:
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Survival before = 100%
Event at time = 0.4
Contribution to Kaplan-Meier estimate:
fractions decimal
own contribution 1/6 0.16667
from subject 1 1/6*1/5 0.03333
sum 0.2000
Survival after = 100% - (1/6 + 1/6*1/5)
= 100% - 20% = 80%
Subject 3:
---------------------------
Survival before = 80%
Event at time = 0.51
Contribution to Kaplan-Meier estimate:
fractions decimal
own contribution 1/6 0.16667
from subject 1 1/6*1/5 0.03333
sum 0.2000
Survival after = 80% - (1/6 + 1/6*1/5)
= 80% - 20% = 60%
Subject 4:
---------------------------
Survival before = 60%
No event until time = 0.51
Re-distribute mass 0.2 to remaining 2 subjects
Survival after = 60%
Subject 5:
---------------------------
Survival before = 60%
No event until time = 0.7
Re-distribute mass 0.3 to remaining 1 subject
Survival after = 60%
Subject 6:
---------------------------
Survival before = 60%
Event at time = 0.73
Contribution to Kaplan-Meier estimate:
fractions decimal
own contribution 1/6 0.16667
from subject 1 1/6*1/5 0.03333
from subject 4 1/6*1/2 0.08333
1/6*1/5*1/2 0.01667
from subject 5 1/6*1/1 0.16667
1/6*1/5*1/1 0.03333
1/6*1/2*1/1 0.08333
1/6*1/5*1/2*1/1 0.01667
sum 0.6000
Survival after = 60% - (1/6 + 1/6*1/5 + 1/6*1/2 + 1/6*1/5*1/2 + 1/6*1/1 + 1/6*1/5*1/1 + 1/6*1/2*1/1 + 1/6*1/5*1/2*1/1)
= 60% - 60% = 0%
Summary table:
time n.risk n.event n.lost surv
1 0.00 6 0 0 100
2 0.35 6 0 1 100
3 0.40 5 1 0 80
4 0.51 4 1 1 60
5 0.70 2 0 1 60
6 0.73 1 1 0 0
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