Estimating the % survival, evented, and censored at each 3 month interval. If you use the Kaplan Meier curve (with the barely visible tic marks) and more importantly the cumulative overall survival at each 3 month interval and patients at risk you can estimate when the censors occur, how many have evented, and how many patients are left at risk. How this is possible is that you use the at risk patients and the survival % at each interval (you can back calculate the survival at each interval by using cumulative survival and multiplying the successive survival %'s). For example, if 90% of patients live from 0-3 months, and 80% of those exiting 0-3 months survive until at least 6 months, then 90% x 80% = 72% cumulative survival to 6 months (which would be the line in Kaplan meier at that data point).
Using this methodology, I found the following (AR=at risk, EV=evented(death), CE=censored, CS%=cumulative survival at month, match to Kaplan Meier):
Please feel free to comment on these findings. I am interested to hear your analysis. These findings indicate 23/40 bavituximab patients (1mg + 3mg) were censored after 9 months, and7 of the 1mg were censored after 12 months. If those patients are added back to the OS calculation once evented (e.g. evented at 14 months), then it would positively impact OS results. Bascially, the reason for censoring is likely survival, and not anything malicious by management. As said, 1mg arm is much better with censoring later than 3mg, but if 3mg is acting like 1mg, then we can assume that these patients are living longer also.
Docetaxel survival data
Mo AR EV CE CS%
0 38 0 0 100%
3 32 6 0 84%
6 18 20 0 47%
9 9 25 4 31%
12 6 26 6 26%
13 3 28 7 16%
14 1 29 8 8%
15 0 29 9 0%
Bavituximab 1mg survival data
months AR EV CE CS%
0 40 0 0 100%
3 35 5 0 88%
6 27 11 2 72%
9 21 14 5 63%
12 10 18 12 45%
13 4 19 17 36%
14 2 19 19 36%
15 2 19 19 36%
Bavituximab 3mg survival data
months AR EV CE CS%
0 39 0 0 100%
3 29 6 4 82%
6 21 12 6 64%
9 14 13 12 60%
12 7 14 18 53%
13 3 15 21 41%
14 3 15 21 41%
15 3 15 21 41%
