Table 1. The total 41 risk sets for the example data (taken from Appendix D in reference 10).

Ordered Risk Set	Failure Time	Number of Subjects At Risk				Risk Factor Status for the Relapsed Patients
(j)	(Days)	n 11j	n 10j	n 01j	n 00j	(CMV a , MTX b )
1	32	26	40	12	55	(0,0)
2	47	25	40	12	54	(0,0) and (0,0)
3	48	25	40	12	52	(0,0)
4	55	24	39	12	51	(1,1)
5	64	23	39	11	51	(1,1)
6	74	22	39	11	51	(1,1)
7	76	20	39	11	51	(1,1)
8	84	19	39	10	49	(1,0)
9	93	18	38	10	49	(1,0)
10	100	18	37	10	49	(1,0)
11	104	18	36	10	49	(0,0)
12	109	17	35	10	47	(1,1)
13	110	16	35	10	47	(1,1)
14	113	15	35	10	47	(1,1)
15	115	14	35	10	47	(1,0)
16	120	14	34	10	47	(1,0)
17	122	14	33	10	47	(1,1)
18	129	13	33	10	46	(0,1)
19	157	13	33	9	46	(1,0)
20	192	12	32	9	42	(1,1)
21	211	11	32	9	41	(0,0)
22	219	11	32	9	40	(1,1)
23	230	10	32	9	39	(0,0)
24	242	10	32	9	38	(0,0)
25	248	10	32	9	37	(0,0)
26	268	10	32	9	36	(1,0)
27	272	10	31	9	36	(1,0)
28	273	10	30	9	36	(1,1)
29	381	8	28	8	35	(0,0)
30	383	8	28	8	34	(0,0)
31	390	8	28	8	33	(1,0)
32	421	8	27	8	30	(0,0)
33	422	8	27	8	29	(0,0)
34	456	8	27	8	28	(1,0)
35	467	8	26	7	28	(1,0)
36	486	8	24	7	28	(0,0)
37	606	8	24	6	25	(1,1)
38	609	7	24	6	25	(1,0)
39	625	7	23	6	25	(1,0)
40	662	7	22	6	24	(0,0)
41	748	7	20	6	23	(0,0)

^a Cytomegalovirus immune status: 1 if CMV positive, and 0 if otherwise.

^b Methotrexate usage: 1 if MTX being used, and 0 if otherwise.