Table 7.

Logistic regression analysis of potential risk factors on implant failure in spine metastasis

Independent variable	r2	Odds ratio (95% confidence interval)	Standard error	p-value
Age at operation	<0.01	0.99 (0.93–1.06)	0.03	0.99
Gender	<0.01	0.82 (0.21–3.28)	0.71	0.78
Survival period	<0.01	1.00 (1.00–1.00)	0.00	0.61
Primary tumor (ref: slow growth)	0.15
Moderate growth		0.00 (0.00–0.00)	-	1.00
Rapid growth		0.00 (0.00–0.00)	-	1.00
Spine level involved (ref: junction area)	0.01
Semi-rigid spine		0.87 (0.20–3.82)	0.76	0.86
Mobile spine		0.32 (0.03–3.09)	1.16	0.33
Construct length	<0.01	0.91 (0.60–1.36)	0.21	0.63
Levels of decompression	0.04	0.22 (0.03–1.77)	1.07	0.15
Utilization of fusion materials (ref: no)	0.01
Yes		2.04 (0.51–8.21)	0.71	0.32
Application of radiotherapy either before or after spine operation (ref: no)	0.05
Yes		0.09 (0.01–0.75)	1.08	0.03

Dependent variable: implant failure.

r², coefficient of multiple determination; Ref, reference.