Table II.

Sensitivity analysis and model comparisons

Correlation structure	Gaussian correlation			Exponential correlation			Compound Symmetry (ρ=0.3)
survival distribution	piecewise exponential	exponential	one exponential for both groups	piecewise exponential	exponential	one exponential for both groups	piecewise exponential	exponential	one exponential for both groups
β0	108.43	108.69	108.67	108.32	108.57	108.54	107.77	108.09	108.07
β1	12.02	11.77	11.80	12.12	11.88	11.91	11.39	11.10	11.13
β2	3.99	4.01	4.00	4.01	4.02	4.02	4.18	4.22	4.21
β3	0.09	0.13	0.13	0.09	0.14	0.14	0.08	0.10	0.10
β4	−1.36	−1.40	−1.40	−1.38	−1.42	−1.42	−1.23	−1.29	−1.29
β5	−0.06	−0.10	−0.09	−0.06	−0.09	−0.09	−0.05	−0.06	−0.06
σ	18.22	18.28	18.28	17.96	18.02	18.01	18.84	18.90	18.90
τ	11.35	11.36	11.36	9.97	9.98	9.97	10.73	10.72	10.73
ν	9.95	9.96	9.96	11.70	11.72	11.71	9.61	9.62	9.59
α	0.02	0.02	0.02	0.15	0.15	0.15	--	--	--
BIC	11595.70	11628.53	11624.42	11596.48	11628.82	11624.49	11648.46	11680.84	11676.40