TABLE 2.

Result of multivariate Cox regression analysis for OS and PFS

Variable	Category	Overall survival			Progression‐free survival
		Hazard ratio	95% CI	p‐value	Hazard ratio	95% CI	p‐value
Age (y/o)	≥60	1.46	0.74‐2.86	0.277	1.07	0.69‐1.67	0.765
Gender	Men	1.81	0.89‐3.68	0.101	1.27	0.83‐1.96	0.275
ISS	≥2	1.48	0.75‐2.91	0.264	1.62	1.02‐2.59	0.043
PS	≥2	0.29	0.08‐1.01	0.052	0.80	0.43‐1.48	0.474
M protein	IgG	0.55	0.28‐1.10	0.090	0.83	0.52‐1.31	0.415
Maintenance	+	0.92	0.46‐1.82	0.807	0.70	0.45‐1.08	0.106

Note: An ISS ≥2 predicted worse PFS, while other factors failed to predict OS and PFS.

Abbreviations: CI, confidence interval; ISS, International Staging System; OS, overall survival; PFS, progression‐free survival; PS, performance status.