Table 2.

Cox proportional hazards model for variables independently associated with overall survival. Inputs into the model included: age, gender, race, population status of zip code, income level, insurance status, Charlson/Deyo comorbidity score, induction radiation therapy status, early versus delayed surgery interval, extent of surgical resection, number of pathologically positive lymph nodes, surgical margins, thirty-day readmission status, and adjuvant therapy status.

Variable	Hazard Ratio (95% CI)	P value
Age (per year increase)	1.02 (1.01–1.03)	<0.001
Caucasian race	0.74 (0.57–0.95)	0.02
Charlson-Deyo Score (ref: 0)
1	1.21 (1.03–1.43)	0.03
≥2	1.14 (0.83–1.56)	0.42
Positive Lymph Nodes (per node)	1.04 (1.01–1.06)	0.004
Delay ≥ 3 months in interval from induction therapy initiation to surgery	1.21 (1.04–1.43)	0.02
Positive surgical margins (≥R1)	1.73 (1.35–2.20)	<0.001