Table 2 Calculations for the Kaplan–Meier estimate of the survival function for the treatment 2 data from Table 1
Patient number | Survival time (days) | Number known to be alive (ri) | Deaths (di) | Proportion surviving (pi) | Cumulative proportion surviving (S [t]) |
|---|---|---|---|---|---|
| Â | 0 | Â | Â | Â | 1 |
1 | 1 | 8 | Â | Â | Â |
2 | 1 | 8 | 2 | (8 - 2)/8 = 0.750 | 1 Ă— 0.750 = 0.750 |
3 | 4 | 6 | 1 | (6 - 1)/6 = 0.833 | 0.750 Ă— 0.833 = 0.625 |
4 | 5 | 5 | 1 | (5 - 1)/5 = 0.800 | 0.625 Ă— 0.800 = 0.500 |
5 | 6+ | Â | Â | Â | Â |
7 | 9 | 3 | 1 | (3 - 1)/3 = 0.667 | 0.500 Ă— 0.667 = 0.333 |
8 | 9+ | Â | Â | Â | Â |
11 | 22 | 1 | 1 | (1 - 1)/1 = 0.00 | 0.333 Ă— 0.00 = 0.000 |