. Author manuscript; available in PMC: 2011 Jun 24.

Published in final edited form as: Cancer Epidemiol Biomarkers Prev. 2008 Dec;17(12):3419–3426. doi: 10.1158/1055-9965.EPI-08-0560

Table 3.

Association between Vitamin C intake and risk of head and neck squamous cell carcinoma stratified by HPV16 serology

HPV16 serology	Vitamin C	Cases		Controls		OR^*	95% CI
HPV16 serology	Vitamin C	n	%	n	%	OR^*	95% CI
Negative	Tertile 1	83	30.7	128	26.0	Referent
	Tertile 2	45	16.7	154	31.2	0.62	0.38, 0.99
	Tertile 3	60	22.2	158	32.1	0.81	0.51, 1.28
Positive	Tertile 1	25	9.3	18	3.7	Referent
	Tertile 2	34	12.6	21	4.3	1.35	0.56, 3.25
	Tertile 3	23	8.5	14	2.8	1.83	0.69, 4.84
							P_interaction=0.21

Odds ratios adjusted for age, gender, race, pack-years of smoking, alcohol, total energy intake, BMI and education