Table 4.

Summary of utility values

	ACDF (n = 10)*	CDA (n = 18)*	P-value
NDI
Preoperation utility	0.49 ± 0.1	0.50 ± 0.1	0.66
12 months	0.61 ± 0.21	0.65 ± 0.12	0.56
24 months	0.70 ± 0.1	0.64 ± 0.11	0.11
Total QALYs 1 year	0.16 ± 0.15	0.13 ± 0.11	0.57
Total QALYS 2 years	0.37 ± 0.23	0.27 ± 0.2	0.27
SF-36
Preoperation utility	0.47 ± 0.10	0.51 ± 0.12	0.34
12 months	0.72 ± 0.13	0.68 ± 0.17	0.52
24 months	0.71 ± 0.13	0.68 ± 0.16	0.69
Total QALYs 1 year	0.23 ± 0.16	0.15 ± 0.13	0.15
Total QALYS 2 years	0.47 ± 0.30	0.32 ± 0.26	0.19

^*Values given as mean ± standard deviation.