Table 3.

Univariate analysis of common prognostic markers and response to PCLI as predictors of overall survival

Prognostic variable	Proportional hazard ratio	95% CI	P
Age > 65 y	1.15	0.73-1.67	.60
Albumin < 3.5 g/dL	1.23	0.84-1.78	.28
β2M > 3.5 mg/dL	1.47	1.01-2.14	.042*
Creatinine > 1.4	1.51	1.02-2.22	.042*
Hemoglobin < 10 g/dL	1.20	0.82-1.74	.34
Serum M-spike response < 50%	1.64	1.13-2.38	.009*
PCLI response < 60%	1.56	1.08-2.25	.019*
Initial PCLI
≥ 3%	2.54	1.50-4.08	< .001*
≥ 1%	1.42	0.96-2.12	.08

β₂M indicates β₂-microglobulin; CI, confidence interval; and PCLI, plasma cell labeling index.

^*Statistically significant.