Table 5. Assessment of significant differences among the anchoring groups in both the NDI and mJOA scoring systems at baseline, 1-year follow-up, and baseline to 1-year change in scores across all anchoring groups. Bonferroni post-hoc test was used to assess these differences between anchoring groups.

Anchoring group	NDI				mJOA
	Pre-operative score	Change in score	Post-operative score		Pre-operative score	Change in score	Post-operative score
Much better versus better	1.0	1.0	0.691		1.0	1.0	0.6
Much better versus neither	1.0	0.068	0.167		1.0	1.0	1.0
Much better versus worse	1.0	0.018*	0.012*		1.0	0.121	0.044*
Much better versus much worse	1.0	0.185	0.921		1.0	0.815	0.489
Better versus neither	1.0	0.515	1.0		1.0	1.0	1.0
Better versus worse	1.0	0.21	0.293		1.0	1.0	1.0
Better versus much worse	1.0	1.0	1.0		1.0	1.0	1.0
Neither versus worse	1.0	1.0	1.0		1.0	1.0	1.0
Neither versus much worse	1.0	1.0	1.0		1.0	1.0	1.0
Worse versus much worse	1.0	1.0	1.0		1.0	1.0	1.0

*, represent a significance of P<0.05. NDI, neck disability index; mJOA, modified Japanese Orthopaedic Association.