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 partners used condoms 100 percent of time was basically put into a couple of groups based on the solutions to issue “Did their lover’s cock actually ever contact the hole of vagina as opposed to a beneficial condom?” When the subjects always replied “no” for each and every work out of genital sex within the eight-month period, these people were coded because with got “zero genital contact in the place of a good condom.” Analyses had been performed as the described significantly more than, which have four categories of the latest frequency regarding condom have fun with (completely without the vaginal contact rather than a good condom, completely which includes or an unidentified regularity of genital get in touch with in place of a great condom White Sites dating, and around three teams lower than 100 percent, because demonstrated a lot more than).
Likewise, Cox proportional-dangers models were utilized to choose risk products toward detection off experience cervical squamous intraepithelial lesions within the seven months before confirmed Pap take to (on the basis of a past observation that almost all sores can be found appropriate experience infection 23 ). A great 51-go out lag before every see was integrated because the 51 weeks are the brand new shortest observed interval amongst the time a female earliest got sex additionally the big date away from recognition out of an instance lesion during the this study. Analysis to own such subjects had been censored following the very first identification out of an instance lesion.
Abilities
The mean (±SD) age of the fresh 82 subjects from the subscription is actually 19.3±0.7 many years. The victims finished 709 check outs. This new suggest follow-up day is actually 33.9±11.8 months, this new imply level of check outs for every girl are 8.6±2.9, therefore the average time passed between check outs was 4.step one months. Journal research had been 90.eight per cent complete, and you may condom data have been registered to the 99.3 per cent out of days one to gender try reported.
Table dos
The new twelve-day collective incidence out of a primary HPV infection once earliest intercourse are 37.dos % (95 per cent believe period, twenty-seven.2 so you can 49.cuatro %). All in all, 126 event particular-certain infections have been identified inside the forty girls after they basic had gender ( Table 2 ). Event infection was in fact understood when you look at the about three females ahead of they advertised that have intercourse the very first time, and you to self-confident having HPV sort of 51, that to possess HPV type 6, and another to own HPV brands 40, 61, and you can 66. The brand new twenty four-few days cumulative incidence off cervical squamous intraepithelial sores is 15.0 percent (95 percent trust interval, 8.step 3 to twenty six.dos percent).