Table 4.

One-variable and probabilistic sensitivity analyses, Ranges and Distributions.

	One-Variable Sensitivity Analysis			Probabilistic Sensitivity Analysis
Variable	Lower	Base case	Upper	Distribution (Parameters)
Failure
CC	0.028	0.043	0.060	Beta (mean=.043, SE=.008)
Spacer	0.020	0.027	0.036	Beta (mean=.027,SE=.004)
DS	0.004	0.012	0.037	Beta (mean=.012,SE=.008)
DS AE rate	0.022	0.054	0.099	Beta (α = 7, β = 122)
IRF discharge rate	0.013	0.039	0.078	Beta (α = 5, β = 124)
Proportion 1 Level	0.25	0.50	0.75	Triangular (0.25,0.50,0.75)
Fusion rate	0.17	0.31	0.47	Beta (α = 11, β = 24)
DS after CC failure	0.80	0.90	1.00	Triangular (0.80,0.90,1.00)
Utility Increase
CC	0.000	0.016	0.030	Fixed
Spacer	0.120	0.144	0.168	Normal (0.144, 0.013)
DS, 3 mo	0.154	0.181	0.207	Normal (0.181, 0.014)
DS, 12 mo	0.124	0.151	0.179	Normal (0.151, 0.014)