Table 3.

Hazard Ratios for Patients With OPC Known to be HPV Positive and With Imputed HPV-Positive Status by RPA Stage Adjusted for Age, Pack-Years, and Chemotherapy Use

RPA stage	No. (%) of Patients	Analysis by Type of HPV-Positive Status
		Known		Imputed
		Crude HR (95% CI)	Adjusted* HR (95% CI)	Crude HR (95% CI)	Adjusted* HR (95% CI)
IA	195 (29.5)	1.0 (referent)	1.0 (referent)	1.0 (referent)	1.0 (referent)
IB	219 (33.1)	2.5 (1.1 to 5.6)	2.1 (.9 to 4.8)	1.4 (.9 to 2.3)	1.4 (.8 to 2.2)
II	171 (25.9)	4.4 (2.0 to 9.8)	3.4 (1.5 to 7.8)	2.8 (1.8 to 4.3)	2.6 (1.6 to 4.3)
III	76 (11.5)	8.2 (3.7 to 18.5)	5.0 (2.0 to 12.2)	6.4 (4.1 to 9.9)	5.2 (3.0 to 8.9)

Abbreviations: HPV, human papillomavirus; HR, hazard ratio; OPC, oropharyngeal cancer; RPA, recursive partitioning analysis.

^*Adjusted for age, smoking pack-years, and chemotherapy use.