Potential risk factors included the total number of instances of vaginal intercourse (continuous variable), the number of new partners (0, 1, or >1), the frequency of condom use by partners (<5 percent, 5 to 49 percent, 50 to 99 percent, or 100 percent), the partner's circumcision status (circumcised, uncircumcised, or unknown), and the partner's number of previous partners (0, ?1, or unknown). The frequency of condom use was calculated by dividing the number of condoms used for vaginal intercourse by the number of instances of vaginal intercourse during the eight-month study period. If multiple new partners were reported during an eight-month period, the circumcision status and previous number of partners were summarized ( Table 1 ). The percentage of days that lacked diary entries was calculated to assess potential confounding created by missing data. The effect of the frequency of condom use was evaluated by multivariate analysis with the inclusion of other variables that were found to be significant (P<0.10) in univariate analyses. Similar analyses were performed to evaluate risk factors for high-risk types of HPV (16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 67, 68, 73, and 82), 20,21 low-risk types (6, 11, 40, 42, 54, 55, 57, 61, 62, 64, 69, 70, 71, 72, 81, 83, 84, and CP6108), 20,21 and types 6, 11, 16, and 18 (which are included in quadrivalent vaccine trials 22 ). To evaluate whether the effect of condom use on the risk of HPV infection differed according to the location in the genital tract, similar analyses were performed to examine risk factors for incident cervical and vulvovaginal infections.

In subanalyses, sufferers whose lovers utilized condoms 100 % of time was indeed split up into several categories on such basis as its answers to the question “Did your own lover’s dick actually contact the hole of your own genitals versus an effective condom?” In the event the victims usually responded “no” for each work out-of vaginal sex when you look at the eight-times several months, these were coded because the having had “no genital contact in place of a beneficial condom.” Analyses was indeed did due to the fact described significantly more than, having four types of the fresh regularity regarding condom explore (completely without having any genital contact rather than an excellent condom, 100 percent which includes or a not known regularity of vaginal contact instead a beneficial condom, and you can around three teams less than 100 percent, since the explained over).