. 2010 May 2;11(4):676–692. doi: 10.1093/biostatistics/kxq021

Table 3.

Actual coverage of nominal 95% confidence interval using Jin, IP_T, and IP_Z for β in the AFT model: F₂(t) = F₁(βt), where β = 2, c₁ and c₂ refer to the percentages of censored observations in groups 1 and 2, respectively

Uniform(12, 60)
				log(T₁) ∼ logistic(0, 1)						log(T₁) ∼ N(3, 1)
n₁	n₂	γ₁	γ₂	c₁ (%)	c₂ (%)	Jin (%)	Jin^* (%)	IP_T (%)	IP_Z (%)	c₁ (%)	c₂ (%)	Jin (%)	Jin^* (%)	IP_T (%)	IP_Z (%)
10	10	0.12	0.04	22	18	92.6	91.6	95	95	83	79	78.6	90.0	98	98
10	10	0.04	0.04	12	18	92.0	90.4	95	95	61	80	86.0	89.6	97	95
10	10	0.00	0.04	3	18	91.6	90.4	93	95	32	79	85.0	87.2	97	96
10	10	0.00	0.00	3	6	90.8	90.0	95	95	32	57	91.4	91.8	94	94
10	50	0.00	0.04	3	18	95.0	92.0	95	96	32	79	90.8	92.6	95	95
Uniform(12, 60)
				log(T₁) ∼ logistic(0, 1)						log(T₁) ∼ N(0, 1)
n₁	n₂	γ₁	γ₂	c₁ (%)	c₂ (%)	Jin (%)	Jin^* (%)	IP_T (%)	IP_Z (%)	c₁ (%)	c₂ (%)	Jin (%)	Jin^* (%)	IP_T (%)	IP_Z (%)
10	10	1.5	1.5	67	79	81.8	85.6	96	97	72	86	71.6	85.8	96	98
10	10	1	1	60	72	89.8	91.8	94	96	62	78	83.4	88.6	96	96
20	10	1.5	1.2	67	75	91.0	91.8	96	95	72	82	81.6	85.2	96	97
50	10	1.5	1.2	67	75	93.8	91.2	95	95	72	82	88.8	82.6	96	98
50	50	1.5	1.5	67	79	96.0	96.0	95	97	72	86	94.8	97.2	96	97
Uniform(0.5, 2)
				log(T₁) ∼ logistic(0, 1)						log(T₁) ∼ N(0, 1)
n₁	n₂	γ₁	γ₂	c₁ (%)	c₂ (%)	Jin (%)	Jin^* (%)	IP_T (%)	IP_Z (%)	c₁ (%)	c₂ (%)	Jin (%)	Jin^* (%)	IP_T (%)	IP_Z (%)
10	10	1	1	64	77	84.4	87.4	97	95	68	85	75.8	84.8	95	97
20	10	1.5	1	69	77	90.2	91.4	97	96	75	85	76.4	79.6	97	98
50	10	1.5	1	69	77	92.6	88.8	96	97	75	85	79.8	75.4	95	97
50	50	1.5	1	69	77	96.8	96.0	95	95	75	85	94.6	96.8	95	97
10	10	0	0	46	63	90.6	91.6	96	94	44	70	90.6	90.6	95	96

Variance estimates obtained using bootstrap.