Table 3.

Odds ratios (ORs)^a for oral and pharyngeal, and laryngeal cancers, and corresponding confidence intervals (95%CIs), on non-alcohol energy-adjusted vitamin C intake quintiles. International Head and Neck Cancer Epidemiology (INHANCE) consortium.

	Controls	Oral and pharyngeal cases	OR (95% CI)b	Pstudiesc	Laryngeal cases	OR (95% CI)b	Pstudiesc
I Quintiled	1359	995	1e	<0.001	431	1e	<0.001
II Quintiled	1768	892	0.86 (0.71–1.03)		288	0.64 (0.46–0.89)
III Quintiled	1945	730	0.66 (0.58–0.77)		252	0.53 (0.39–0.72)
IV Quintiled	1956	666	0.62 (0.53–0.74)		210	0.48 (0.38–0.62)
V Quintiled	1968	611	0.54 (0.45–0.65)		221	0.52 (0.40–0.68)
pfor trendf			<0.001			0.006

^aEstimated from multiple logistic regression models adjusted for age, sex, education, race/ethnicity, study center, cigarette smoking status, cigarette intensity, cigarette duration, cigar smoking status, pipe smoking status, alcohol drinking intensity and the interaction between cigarette intensity and alcohol drinking intensity.

^bAs heterogeneity among studies was detected (p<0.1), we reported the mixed-effects estimates derived from the corresponding generalized linear mixed model.

^cP for heterogeneity among studies.

^dThe quantile cut-offs were the following ones:−0.779, −0.367, 0.055,and 0.683.

^eReference category.

^fP for linear trend.