Table 2.

Cox regression analysis of the factors that were significantly associated with survival in the univariate analysis

	Risk ratio	95 %-confidence interval	P
Visceral metastases at the time of RT
no vs. yes	5.42	3.34 – 9.05	<0.001
Other bone metastases at the time of RT
no vs. yes	1.35	0.80 – 2.27	0.26
Time developing motor deficits prior to RT
> 14 days vs. 8–14 days vs. 1–7 days	1.68	1.30 – 2.17	<0.001
Ambulatory status prior to RT
ambulatory vs. not ambulatory	2.34	1.56 – 3.51	<0001
Involved vertebrae (N)
1–3 vs. ≥ 4	1.18	1.01 – 1.37	0.032
ECOG Performance status
1–2 vs. 3 vs. 4	2.40	1.64 – 3.53	<0.001