Table 4. The effect of HPV status on Oropharyngeal Cancer (OPC).

			Direct Effect		Indirect Effect		Total Effect
	Cases (N)	Controls (N)	Effect Estimate	(95%CI)	Effect Estimate	(95%CI)	Effect Estimate	(95%CI)
Modified Fagerström Score
HPV Positive-OPC	281	567	0.99	(0.41, 2.39)	1.15	(1.03, 1.28)	1.05	(0.67, 1.65)
HPV Negative-OPC	118	567	2.15	(1.24, 3.73)	1.42	(1.14, 1.77)	3.06	(1.65, 5.66)

Models are adjusted for age, gender, ethnicity, education, smoking status, age started smoking, and family history of HNC cancer, and average daily alcohol consumption (grams/day). The table demonstrates the direct effect of nicotine dependence by HPV status within Oropharyngeal Cancer (OPC) cases. The effects are demonstrated by the modified Fagerström (the combination of only Score 1: time to first cigarette and score 4: smoking intensity).