Table 1.

Simulation results based on 1000 Monte Carlo data sets when the true model is the PH or PO model with baseline density f₀(t). Mean is Monte Carlo mean of the 1000 estimates of β when the true model is fitted, SD is their Monte Carlo standard deviation, SE is the average of the 1000 estimated delta method standard errors, and CP is Monte Carlo coverage probability, expressed as a percent, of 95% Wald confidence intervals. For right-censored data, SNP and PL indicate fitting using the SNP approach with K and the base density chosen via HQ and partial likelihood, respectively. All of the AFT, PH, and PO models were fitted to each data set under right-censoring; the columns AFT, PH, and PO indicate the percentage of 1000 data sets for which that model was chosen based on HQ, and Correct indicates the percentage of data sets supporting the PH model; see the text. For interval-censored data, only SNP was used. (a) PH model: true value of β = 2.0 in all cases. (b) PO model: true value of β = 2.0 (lognormal, Weibull) or β = −2.0 (log-mixture).

f0(t)	n	Cens. rate	Method	Mean	SD	SE	CP	AFT	PH	PO	Correct
(a) True PH model
Right-censored data
lognormal	200	25%	SNP	2.02	0.32	0.31	95.4	9.4	86.5	5.2	86.5
			PL	2.00	0.32	0.32	96.3
Weibull	200	25%	SNP	2.02	0.31	0.31	95.5	86.7	88.0	2.8	97.2
			PL	2.01	0.32	0.32	96.3
gamma	200	25%	SNP	2.06	0.32	0.31	94.3	66.8	81.6	6.3	81.6
			PL	2.02	0.32	0.32	95.2
log-mixture	200	25%	SNP	2.04	0.34	0.33	94.9	2.4	73.6	24.0	73.6
			PL	2.02	0.33	0.33	95.5
Interval-censored data
gamma	200	18% right, 82% interval	SNP	2.04	0.30	0.29	93.9
log-mixture	200	20% right, 80% interval	SNP	2.04	0.30	0.30	94.8
(b) True PO model
Right-censored data
lognormal	200	25%	SNP	2.01	0.18	0.18	94.6	0.7	2.2	97.1	97.1
Weibull	200	25%	SNP	2.00	0.46	0.45	94.6	29.4	19.7	65.1	65.1
log-mixture	200	25%	SNP	−1.99	0.46	0.45	95.3	1.4	15.4	83.2	83.2
Interval-censored data
log-mixture	200	20% right, 80% interval	SNP	−2.01	0.48	0.47	95.7