Table 1.

Prevalence of oral HPV infection among male participants in the HITCH cohort study

Overall (n = 222)Type-specific (n = 7992)a
Total, n (%)Prevalence, n (%)Unadjusted PR (95% CI)Adjusted PR (95% CI)bPrevalence, n (%)Unadjusted PR (95% CI)Adjusted PR (95% CI)b
Age, years
 ≤21100 (45.1)5 (5.0)1.00 (ref)8 (0.10)1.00 (ref)
 >21122 (54.9)11 (9.0)1.80 (0.65–5.03)13 (0.16)1.33 (0.43–4.13)
Smoking
 Never124 (55.9)4 (3.2)1.00 (ref)1.00 (ref)8 (0.10)1.00 (ref)1.00 (ref)
 Ever98 (44.1)12 (12.2)3.80 (1.26–11.43)3.72 (1.23–11.23)13 (0.16)2.06 (0.64–6.59)2.04 (0.64–6.51)
Lifetime no. any sex partnersc
 1–476 (34.2)2 (2.6)1.00 (ref)1.00 (ref)4 (0.05)1.00 (ref)1.00 (ref)
 5–970 (31.5)4 (5.7)2.17 (0.41–11.53)2.09 (0.40–10.83)5 (0.06)1.36 (0.22–8.55)1.38 (0.23–8.42)
 >976 (34.2)10 (13.2)5.00 (1.13–22.14)4.69 (1.17–18.89)12 (0.15)3.00 (2.53–15.70)3.09 (0.71–13.50)
Frequency of oral sex on female partner
 Never/rarely48 (21.6)1 (2.1)1.00 (ref)1.00 (ref)1 (0.01)1.00 (ref)1.00 (ref)
 Sometimes126 (56.8)10 (7.9)3.81 (0.50–29.10)3.76 (0.49–28.59)13 (0.16)4.95 (0.64–38.27)4.92 (0.64–38.00)
 Most times/always48 (21.6)5 (10.4)5.00 (0.60–41.41)4.84 (0.59–39.94)7 (0.09)7.00 (0.80–61.49)6.89 (0.77–61.71)
 Average effect of each additional increase in frequency1.49 (0.78–2.86)1.46 (0.78–2.74)1.64 (0.86–3.13)1.62 (0.84–3.15)
 If HITCH partner is: genital HPV-positive
  Never/rarely/sometimesd97 (74.6)10 (10.3)1.00 (ref)1.00 (ref)6 (2.40)1.00 (ref)1.00 (ref)
  Most times/always33 (25.4)5 (15.2)1.47 (0.54–4.00)1.42 (0.52–3.85)5 (6.41)2.69 (0.71–10.22)2.72 (0.71–10.33)
  Average effect of each additional increase in frequency1.32 (0.64–2.70)1.27 (0.62–2.62)2.26 (1.01–5.08)2.33 (1.00–5.43)
 If HITCH partner is: genital HPV-negative
  Never/rarely/sometimesd76 (83.5)1 (1.3)1.00 (ref)1.00 (ref)8 (0.13)1.00 (ref)1.00 (ref)
  Most times/always15 (16.48)0NCNC2 (0.12)0.91 (0.19–4.51)0.89 (0.18–4.46)
  Average effect of each additional increase in frequency1.32 (1.01–1.73)1.16 (0.79–1.69)1.08 (0.49–2.39)1.06 (0.49–2.31)
Total episodes of vaginal sex
 <3560 (27.4)4 (6.7)1.00 (ref)1.00 (ref)4 (0.05)1.00 (ref)1.00 (ref)
 35–6046 (21.0)2 (4.4)0.65 (0.12–3.42)0.61 (0.12–3.08)2 (0.03)0.65 (0.12–3.42)0.63 (0.12–3.20)
 >60–10064 (29.2)2 (3.1)0.47 (0.09–2.48)0.40 (0.07–2.20)5 (0.06)1.17 (0.22–6.33)1.06 (0.17–6.61)
 >10049 (22.4)7 (14.3)2.14 (0.66–6.92)1.87 (0.59–5.91)8 (0.10)2.45 (0.74–8.08)2.25 (0.69–7.32)
Frequency of vaginal sex per week
 <363 (28.6)3 (4.8)1.00 (ref)1.00 (ref)3 (0.04)1.00 (ref)1.00 (ref)
 3–460 (27.3)4 (6.7)1.40 (0.33–6.02)1.35 (0.32–5.77)5 (0.06)1.75 (0.39–7.82)1.72 (0.39–7.59)
 >4–654 (24.6)2 (3.7)0.78 (0.13–4.50)0.76 (0.13–4.44)2 (0.03)0.78 (0.13–4.50)0.77 (0.13–4.47)
 >643 (19.6)6 (14.0)2.93 (0.77–11.12)2.59 (0.68–9.92)9 (0.11)4.40 (1.09–17.73)4.10 (0.92–18.27)
Days since last vaginal sex
 <234 (15.5)3 (8.8)1.00 (ref)1.00 (ref)5 (0.06)1.00 (ref)1.00 (ref)
 2–2.583 (37.9)5 (6.0)0.68 (0.17–2.71)0.69 (0.17–2.77)6 (0.08)0.49 (0.10–2.31)0.49 (0.10–2.37)
 >2.5–555 (25.1)5 (9.1)1.03 (0.26–4.05)1.11 (0.27–4.58)6 (0.08)0.74 (0.16–3.46)0.78 (0.15–4.01)
 >547 (21.5)2 (4.3)0.48 (0.08–2.74)0.49 (0.08–2.88)2 (0.03)0.29 (0.05–1.84)0.29 (0.04–1.95)
Concurrent partner status
 None183 (82.4)9 (4.9)1.00 (ref)1.00 (ref)13 (0.16)1.00 (ref)1.00 (ref)
 Either29 (13.1)2 (6.9)1.40 (0.32–6.19)1.34 (0.30–6.09)3 (0.04)1.46 (0.30–7.11)1.43 (0.28–7.22)
 Both10 (4.5)5 (50.0)10.17 (4.17–24.78)9.85 (3.95–24.57)5 (0.06)7.04 (2.74–18.08)6.94 (2.69–7.22)
Oral infection in partner
 No213 (96.8)14 (6.6)1.00 (ref)1.00 (ref)18 (0.23)1.00 (ref)1.00 (ref)
 Yes7 (3.2)2 (28.6)4.35 (1.21–15.62)5.29 (1.35–20.75)3 (0.04)144.32 (30.58–681.13)167.58 (34.40–816.28)
Genital infection in partner
 No91 (41.2)1 (1.1)1.00 (ref)1.00 (ref)10 (0.13)1.00 (ref)1.00 (ref)
 Yes130 (58.8)15 (11.5)10.50 (1.41–78.44)9.91 (1.39–70.88)11 (0.14)25.14 (9.79–64.58)25.28 (9.61–66.45)
Genital infection in self
 No94 (42.5)2 (2.1)1.00 (ref)1.00 (ref)9 (0.11)1.00 (ref)1.00 (ref)
 Yes127 (57.5)14 (11.0)5.18 (1.20–22.33)4.83 (1.21–19.19)12 (0.15)26.93 (11.33–64.03)27.17 (11.40–64.80)

Abbreviation: NC, not calculable due to zero cells.

  • aBased on Poisson regression analysis for which each HPV-type outcome represented an individual observation, resulting in 36 outcomes per person. Among men, 0.26% (21/7,992) oral HPV-type outcomes were positive. Generalized estimating equations were used to account for multiple observations per individual.

  • bAdjusted for age (≤21 vs. >21).

  • cAny sex includes vaginal, oral, and anal.

  • dCategories collapsed due to zero cells.