Following the publication of this paper we received some important observations on the statistical proof used and the way the results were presented in the tables and figure. We have taken them into account and are responding to the same.
For the comparison of the prevalence of HPV infection in men and women, we used the MacNemar test. This test is used to prove a hypothesis of equality of proportions in non-independent groups. In this case the groups of men and women are not independent because they are sexual partners. Table 1 shows that the prevalence of HPV is greater in men than in women (20.4% vs 13.7%, p value = 0.0009). There were no statistically significant differences between type specific infection in men and women; only in types HPV31, HPV53, HPV55, HPV61 and HPV84 (Table 1 and Figure 1).
Table 1. Prevalence of HPV DNA in 504 heterosexual couples in central Mexico, according to sex
Figure 1. Type specific prevalence of HPV infection in a group of heterosexual couples in central Mexico, according to sex
The analysis of known risk factors for HPV infection was carried out separately for men and women. Non-conditional logistic regression was performed. When stratifying by sex we do not need to consider the condition of sexual partners. This part of the analysis was performed in this way, as it allows us to include explanatory variables in men - variables that cannot be defined in women, such as circumcision, use of condoms, and some specific characteristics on sexual risk behaviors. In women it allows us to consider, in addition to characteristics of their own sexual behaviors, characteristics of their male partner's sexual behavior - circumcision, use of condoms, etc. (Table 2). The last section of the study focuses on assessing the risk of HPV infection in women, considering the presence of HPV infection in their sex partners as an explanatory variable. Thus we find that women whose sexual partners are HPV positive have 5.15 times greater risk of HPV, compared to those whose partners are HPV negative (CI 95% 3.01, 8.82). Indeed, what matters to us in this part is proving that the variable "presence of HPV in male partner" be associated with the presence of HPV in the female. We do not seek to compare the risk of HPV infection between men and women (Table 3).
Table 2. Sociodemographic and sexual conduct characteristics associated with the presence of HPV DNA among 504 heterosexual couples in central Mexico, according to sex
Table 3. Risk of HPV infection associated with the status of HPV infection in the sexual partner
We are thankful for your observations and deeply regret the confusion in the results presented.
Parada R, Morales R, Giuliano AR, Cruz A, Castellsagué X, Lazcano-Ponce E: Prevalence, concordance and determinants of human papillomavirus infection among heterosexual partners in a rural region in central Mexico.
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