Risk factors for upper adjacent segment degeneration after multi-level posterior lumbar spinal fusion surgery

Table 6 The Cox proportional hazards for the risk factor of ASD

Factor	Exp (B)^b	95% CI^c for Exp (B)	P value
Pre-op Pfi^a	2.914	1.149–7.392	0.024
Pre-op PI	1.040	1.002–1.080	0.041
Decompressed levels	2.080	1.208–3.580	0.008
Fixed vertebrae	0.634	0.303–1.326	0.226
Interbody fusion levels	0.976	0.616–1.548	0.918

^aPreoperative modified Pfirrmann grade for upper disc of proximal fixed vertebrae
^bExp (B) = relative risk
^cConfidence interval

ISSN: 1749-799X