Table 2.

Multivariate analysis of clinical characteristics affecting OS and EFS

Variable	n/N (%)	Overall survival		Event-free survival
		HR (95% CI)	P†	HR (95% CI)	P†
TT2
Creatinine ≥ 2.0 mg/dL	37/334 (11)	1.75 (1.07, 2.84)	.024	1.70 (1.19, 2.43)	.004
LDH ≥ 190 U/L	114/334 (34)	1.81 (1.24, 2.66)	.002	1.44 (1.13, 1.82)	.003
Cytogenetic abnormalities	108/334 (32)	1.77 (1.20, 2.62)	.004	NS	NS
Randomization to thalidomide	166/334 (50)	NS	NS	0.75 (0.60, 0.93)	.009
t(4;14)	47/334 (14)	1.81 (1.15, 2.85)	.010	1.87 (1.35, 2.57)	< .001
17 gene-defined GEP high-risk*	50/334 (15)	2.47 (1.58, 3.85)	< .001	2.15 (1.56, 2.96)	< .001
TP53 high-risk	35/334 (10)	2.01 (1.22, 3.30)	.006	1.44 (1.00, 2.07)	.049
TT3
Age 65 y or older	50/176 (28)	2.32 (1.04, 5.22)	.041	NS	NS
β2-microglobulin > 5.5 mg/L	38/176 (22)	NS	NS	3.33 (1.68, 6.62)	< .001
Creatinine ≥ 2.0 mg/dL	58/176 (33)	3.54 (1.54, 8.16)	.003	NS	NS
Cytogenetic abnormalities	30/176 (17)	2.42 (1.08, 5.39)	.031	NS	NS
17-gene high-risk	20/176 (11)	3.19 (1.32, 7.68)	.010	3.97 (1.98, 7.97)	< .001
TP53 high-risk	50/176 (28)	2.32 (1.04, 5.22)	.041	2.51 (1.13, 5.57)	.024

The multivariate model uses stepwise selection with entry level 0.1 and variable remains if meets the 0.05 level. A multivariate P > .05 indicates a variable forced into the model, with significant variables chosen by stepwise selection.

HR indicates hazard ratio; CI, 95% confidence interval; P, probability value from Wald χ² test in Cox regression; NS, not statistically significant at the .05 level on multivariate analysis; LDH, lactate dehydrogenase; GEP, gene expression profile; and PI, proliferation index.²⁵

^*17 gene-defined GEP high-risk has been described elsewhere.¹

^†Variables for which P > .05: age, race, sex, isotype, hemoglobin, C-reactive protein, MRI lesions, and albumin.