Table 3.

Multivariable analysis for predictors of overall survival in stage II NPC patients

Variable	HR and 95% CI	P value
Age ≥ 65	2.41 (1.71‐3.4)	<0.0001
Chemotherapy	0.59 (0.39‐0.89)	0.0124
Male	1.39 (0.99‐1.96)	0.0573
Ethnicity
African‐American vs White	1.05 (0.64‐1.74)	0.8341
Asian vs White	0.65 (0.36‐1.18)	0.1568
Other vs White	1.34 (0.74‐2.43)	0.3337
Tumor grade
Grade 2 vs 1	0.82 (0.53‐1.29)	0.3947
Grade 3 vs 1	0.59 (0.4‐0.88)	0.0098
Grade 4 vs 1	0.38 (0.18‐0.78)	0.0083
Median income quartiles (2008‐2012)
Q2 ($38 000‐$47 999) vs Q1 (<$38 000)	0.89 (0.55‐1.45)	0.6383
Q3 ($48 000‐$62 999) vs Q1 (<$38 000)	1.3 (0.8‐2.12)	0.2970
Q4 ($63 000+) vs Q1 (<$38 000)	1.05 (0.63‐1.74)	0.8512
Education quartiles: (%age no high school degree 2008‐2012)
Q2 (13‐20) vs Q1 (≥21)	0.93 (0.6‐1.43)	0.7403
Q3 (7‐12.9) vs Q1 (≥21)	0.86 (0.49‐1.52)	0.6106
Q4 (<7) vs Q1 (≥21)	1.05 (0.63‐1.74)	0.8509
Charlson‐Deyo comorbidity index (CDCI)
CDCI: 1 vs 0	1.23 (0.77‐1.97)	0.3888
CDCI: >1 vs 0	2.82 (1.49‐5.31)	0.0014
Treatment Center
Comprehensive vs Community	1.51 (0.87‐2.62)	0.1440
Academic vs Community	1.16 (0.79‐1.71)	0.4388
Integrated vs Community	1.21 (0.69‐2.11)	0.5094
Nodal status (clinical)
N1 vs N0	1.6 (1.04‐2.46)	0.0340
T stage (clinical)
T2 vs T1	1.07 (0.73‐1.58)	0.7219
Radiation
IMRT vs no IMRT	0.94 (0.67‐1.32)	0.7182
Radiation Dose (Gy)
<70 vs ≥70	1.26 (0.86‐1.84)	0.2423