Table 2 Univariate analysis of patient characteristics, p values

Age at diagnosis, years

 <60 vs. ≥60

HR, 1.72; 95% CI 0.92–3.20; p = 0.09

HR, 0.83; 95% CI 0.48–1.44; p = 0.51

HR, 1.34; 95% CI 0.64–2.79; p = 0.44

HR, 1.03; 95% CI 0.43–2.48; p = 0.95

Primary site

 Oropharynx vs larynx

HR, 1.56; 95% CI 0.81–2.99; p = 0.18

HR, 0.84; 95% CI 0.45–1.55; p = 0.57

HR, 1.82; 95% CI 0.86–3.85; p = 0.12

HR, 1.20; 95% CI 0.47–3.10; p = 0.71

Gender

 M vs F

HR, 0.68; 95% CI 0.24–1.91; p = 0.46

HR, 0.59; 95% CI 0.24–1.48; p = 0.26

HR, 0.69; 95% CI 0.21–2.29; p = 0.55

HR, 0.62; 95% CI 0.15–2.68; p = 0.53

Race

 White vs other

HR, 1.24; 95% CI 0.52–2.95; p = 0.63

HR, 0.98; 95% CI 0.45–2.18; p = 0.98

HR, 1.24; 95% CI 0.5202.95; p = 0.59

HR, 0.37; 95% CI 0.05–2.74; p = 0.33

Tobacco use (pack years)

 <10 vs. ≥10

HR, 2.97; 95% CI 1.48–5.97; p < 0.01

HR, 1.31; 95% CI 0.78–2.21; p = 0.31

HR, 1.92; 95% CI 0.89–4.13; p = 0.10

HR, 1.41; 95% CI 0.59–3.34; p = 0.44

Karnofsky performance score

 >80 vs. ≤80

HR, 0.97; 95% CI 0.50–1.89; p = 0.94

HR, 0.48; 95% CI 0.25–0.92; p = 0.03

HR, 1.23; 95% CI 0.58–2.63; p = 0.59

HR, 1.16; 95% CI 0.47–2.83; p = 0.75

T-stage

 T1/2 vs T3/4

HR, 2.83; 95% CI 1.47–5.44; p < 0.01

HR, 6.47; 95% CI 3.34–12.52; p < 0.01

HR, 2.21; 95% CI 1.42–3.44; p < 0.01

HR, 1.53; 95% CI 0.65–3.64; p = 0.33

N-stage

 N0-1 vs N2/3

HR, 0.98; 95% CI 0.51–1.89; p = 0.96

HR, 1.65; 95% CI 0.90–3.02; p = 0.10

HR, 0.79; 95% CI 0.37–1.67; p = 0.53

HR, 1.26; 95% CI 0.49–3.26; p = 0.63

Post-operative radiation

 Yes vs No

HR, 0.70; 95% CI 0.32–1.52; p = 0.37

HR, 1.01; 95% CI 0.56–1.82; p = 0.97

HR, 0.47; 95% CI 0.16–1.36; p = 0.17

HR, 1.70; 95% CI 0.70–4.12; p = 0.24

HPV

 Positive vs negative

HR, 0.32; 95% CI 0.15–0.67; p < 0.01

HR, 1.00; 95% CI 0.55–1.84; p = 0.98

HR, 0.25; 95% CI 0.10–0.62; p < 0.01

HR, 0.49; 95% CI 0.19–1.27; p = 0.14

Chemotherapy (v none)

 Yes

HR, 1.43; 95% CI 0.34–5.94; p = 0.62

HR, 1.45; 95% CI 0.45

HR, 1.19; 95% CI 0.28–5.03; p = 0.81

HR, 1.90; 95% CI 0.25–14.19; p = 0.50

 Cisplatin, weekly

HR, 1.14; 95% CI 0.23–5.64; p = 0.88

HR, 1.21; 95% CI 0.33

HR, 1.12; 95% CI 0.22–5.77; p = 0.90

HR, 3.57; 95% CI 0.44–29.23; p = 0.24

 Cisplatin, bolus

HR, 1.25; 95% CI 0.25–6.23; p = 0.78

HR, 2.74; 95% CI 0.80

HR, 0.82; 95% CI 0.15–4.59; p = 0.82

HR, 2.20; 95% CI 0.24–19.85; p = 0.48

 Carboplatin

HR, 1.41; 95% CI 0.30–6.59; p = 0.66

HR, 1.15; 95% CI 0.31

HR, 1.79; 95% CI 0.39–8.33; p = 0.46

HR, 0.82; 95% CI 0.07–9.11; p = 0.87

 Cetuximab

HR, 1.91; 95% CI 0.44–8.31; p = 0.39

HR, 1.18; 95% CI 0.34

HR, 1.09; 95% CI 0.23–5.13; p = 0.91

HR, 1.70; 95% CI 0.20–14.11; p = 0.63

 Cetuximab and cisplatin

HR, 0.51; 95% CI 0.05–5.71; p = 0.59

HR, 1.13; 95% CI 0.23

HR, 1.00; 95% CI 0.13–7.77; p = 1.00

HR, 1.36; 95% CI 0.09–21.88; p = 0.83