Table 3.

Calculations for the log-rank test to compare treatments for the data in Table 1

Survival time (days)	Treatment group	Number known to be alive (ri)	Deaths (di)	Risk for death (di/ri)	Number known to be alive from treatment group 2 (r2i)	Expected number of events in treatment group 2 (E2i)
0
1	2	15	2	2/15 = 0.133	8	8 × 0.133 = 1.07
1	2
4	2	13	1	1/13 = 0.077	6	6 × 0.077 = 0.46
5	2	12	1	1/12 = 0.083	5	5 × 0.083 = 0.42
6+	2	11	0	0/11 = 0	4	4 × 0 = 0.00
8	1	10	1	1/10 = 0.100	3	3 × 0.100 = 0.30
9	2	9	1	1/9 = 0.111	3	3 × 0.111 = 0.33
9+	2	8	0	0/8 = 0	2	2 × 0 = 0.00
12	1	7	1	1/7 = 0.143	1	1 × 0.143 = 0.14
15+	1	6	0	0/6 = 0	1	1 × 0 = 0.00
22	2	5	1	1/5 = 0.200	1	1 × 0.200 = 0.20
25+	1	4	0	0/4 = 0	0	0 × 0 = 0.00
37	1	3	1	1/3 = 0.333	0	0 × 0 = 0.00
55	1	2	1	1/2 = 0.500	0	0 × 0 = 0.00
72+	1
						E2 = 2.92