Table 3.

Multivariable Cox proportional hazards regression analysis

Variables	Hazard ratio (95 % CI)	P-value
Sex (reference = women)
Men	1.1 (0.9–1.3)	0.15
Age (years) (reference = 30–60)
< 30	0.3 (0.1–0.9)	0.03
> 60	1.6 (1.4–1.9)	<0.001
Smoking status (reference = non-smoker)
Current	1.3 (1.1–1.5)	0.003
Former smoker	1.0 (0.8–1.3)	0.8
Unknown	1.5 (1.2–1.8)	0.001
Marital status (reference = married)
Divorced	1.7 (1.1–2.7)	0.02
Single	1.2 (1.1–1.4)	0.002
Other	1.3 (1.2–1.5)	<0.001
Occupation status (reference = employed)
Unemployed	1.3 (1.1–1.6)	0.003
Retired	1.5 (1.3–1.9)	<0.001
Other	1.1 (0.9–1.4)	0.18
Deprivation index (reference = most deprived)
Less deprived	0.9 (0.8–0.9)	0.03
Years of incidence (reference = 1994–1999)
2000–2004	0.8 (0.7–0.9)	0.01
2005–2009	0.7 (0.6–0.8)	<0.001
Tumour site (reference = C03 Gum)
C01Base of the tongue	1.3 (1.1–1.7)	0.01
C02 Tongue	1.3 (1.0–1.6)	0.04
C04 Floor of mouth	1.2 (0.9–1.5)	0.11
C05 Unspecified mouth	1.1 (0.5–0.8)	0.62
C06 Palate	1.1 (0.8–1.4)	0.55
Cancer stages (reference = Stage I)
Stage II	1.4 (1.1–1.7)	0.004
Stage III	1.8 (1.5–2.3)	<0.001
Stage IV	2.8 (2.3–3.3)	<0.001
Unknown stage	1.7 (1.4–2.1)	<0.001