Table 4.

Effect of age on HPV infection incidence among men.

	High-risk HPV		Low-risk HPV		HPV 16		HPV 6
	HR (95% CI)	AHR (95% CI)	HR (95% CI)	AHR (95% CI)	HR (95% CI)	AHR (95% CI)	HR (95% CI)	AHR (95% CI)
Three age groups
18–30	1.00		1.00		1.00		1.00
31–44	0.91 (0.81–1.01)	0.87 (0.76–0.99)	0.96 (0.85–1.08)	0.97 (0.84–1.13)	0.69 (0.57–0.83)	0.64 (0.53–0.78)	0.77 (0.63–0.94)	0.75 (0.61–0.92)
45–70	0.84 (0.71–1.00)	0.82 (0.67–0.99)	0.86 (0.72–1.02)	0.82 (0.66–1.01)	0.67 (0.51–0.88)	0.61 (0.46–0.80)	0.56 (0.40–0.78)	0.60 (0.43–0.84)
Five age groups
18–24	1.00		1.00		1.00		1.00
25–34	0.92 (0.81–1.06)	0.85 (0.72–1.00)	1.05 (0.91–1.2)	0.91 (0.77–1.08)	0.82 (0.67–1.01)	0.78 (0.62–0.98)	1.03 (0.82–1.29)	0.99 (0.78–1.26)
35–44	0.86 (0.74–0.98)	0.76 (0.64–0.92)	0.92 (0.80–1.06)	0.84 (0.70–1.02)	0.61 (0.49–0.77)	0.56 (0.43–0.72)	0.67 (0.52–0.87)	0.66 (0.50–0.87)
45–54	0.85 (0.70–1.04)	0.76 (0.59–0.96)	0.90 (0.73–1.11)	0.76 (0.58–0.98)	0.67 (0.48–0.94)	0.61 (0.43–0.86)	0.55 (0.36–0.84)	0.58 (0.38–0.89)
55–70	0.74 (0.55–0.99)	0.68 (0.49–0.94)	0.80 (0.60–1.06)	0.70 (0.51–0.98)	0.57 (0.36–0.92)	0.49 (0.30–0.79)	0.60 (0.35–1.02)	0.65 (0.38–1.12)
Continuous
18–70	0.94 (0.90–0.99)	0.92 (0.86–0.98)	0.96 (0.91–1.00)	0.88 (0.83–0.93)	0.84 (0.78–0.91)	0.81 (0.74–0.88)	0.83 (0.76–0.91)	0.84 (0.76–0.92)

Note: HR=hazard ratio; AHR=adjusted hazard ratio; CI=confidence interval. Associations between age and HPV incidence were assessed using Cox proportional hazards regression. Design variables (country and age) were forced into multivariable models. Race, circumcision status, total and recent numbers of female and male sexual partners, smoking status, education, and marital status were all included in multivariable modeling. Baseline measures were used for all variables. Bold values denote statistical significance in multivariable models.