Table 2. Adjusted odds ratio for all oropharyngeal cancer cases and by subsite compared with controlsa.

	Oropharyngeal cancer		Base of tongue cancer		Tonsil cancer
	OR (95% CI)	P-value	OR (95% CI)	P-value	OR (95% CI)	P-value
Tonsillectomy
No	Ref	–	Ref	–	Ref	–
Yes	0.63 (0.47–0.85)	0.003	1.95 (1.25–3.06)	0.003	0.22 (0.13–0.36)	<0.001
Number of sexual partners
0–1	Ref	–	Ref	–	Ref	–
2–5	2.44 (1.40–4.27)	0.002	2.1 (0.84–5.21)	0.110	3.44 (1.5–7.91)	0.004
6–14	3.81 (2.19–6.60)	<0.001	3.42 (1.42–8.27)	0.006	5.69 (2.49–13)	<0.001
14+	4.65 (2.65–8.18)	<0.001	3.75 (1.52–9.21)	0.004	7.73 (3.33–17.96)	<0.001
Education
Some High School	Ref	–	Ref	–	Ref	–
Completed High School	0.61 (0.41–0.91)	–0.015	0.67 (0.34–1.32)	–0.248	0.59 (0.36–0.97)	–0.037
Some College and above	0.45 (0.31–0.66)	<0.001	0.54 (0.29–1.03)	0.061	0.4 (0.25–0.64)	<0.001
Pack-years
<10 Pack-years	Ref	–	Ref	–	Ref	–
⩾10 Pack-years	2.2 (1.62–2.97)	<0.001	1.91 (1.18–3.09)	0.009	2.23 (1.5–3.32)	<0.001
Insurance
Private	Ref	–	Ref	–	Ref	–
Medicaid/Medicare	0.84 (0.57–1.25)	0.393	0.59 (0.3–1.13)	0.113	0.78 (0.46–1.31)	0.341
None	0.92 (0.55–1.53)	0.743	0.86 (0.37–1.98)	0.717	0.93 (0.51–1.72)	0.823
Other	0.7 (0.45–1.09)	0.112	0.6 (0.3–1.19)	0.1434	0.81 (0.47–1.41)	0.464
Alcohol
⩽1 Drink per week	Ref	–	Ref	–	Ref	–
>1 Drink per week	1.72 (1.16–2.56)	0.007	1.23 (0.67–2.27)	0.503	1.67 (0.98–2.84)	0.058

Abbreviations: CI=confidence interval; OR=odds ratio; Ref=reference value.

^aOdds ratios are all mutually adjusted for in addition to matching factors (age, race, and gender).