Since cervical cancer remains common in Mexico despite an established cytology screening program, the Ministry of Health recently introduced pilot front-line HPV testing into the Mexican cervical cancer screening program (CCSP). Here, we present the key field performance metrics of this population-based study. High-risk HPV DNA (hrHPV) testing was conducted on selfcollected vaginal specimens from 100,242 women aged 25-75 years residing in Morelos State. All hrHPV positive women and a random sample of 3.2% (n 5 2,864) of hrHPV negative participants were referred for colposcopic examination. The main disease endpoint of interest was cervical intraepithelial neoplasia grade 2 or higher (CIN21). We calculated relative risk, positive predictive value and negative predictive value adjusted for screening test verification bias. The overall prevalence of hrHPV was 10.8% (95%CI 10.6-11.0). Women positive for hrHPV had a relative risk of 15.7 for histologically detectable CIN21. The adjusted positive predictive value of the hrHPV test was 2.4% (95%CI 2.1-2.7); whereas the adjusted negative predictive value was 99.8% (95%CI 99.8-99.9). These findings suggest that large-scale vaginal hrHPV testing in a middle-income country can identify women at greater risk of advanced cervical abnormalities in a programmatically meaningful way but care is warranted to ensure that disease not detectable at colposcopy is kept to a minimum. PASS shows areas that need improvement and sets the stage for wider use of hrHPV screening of self-collected vaginal specimens in Mexico.High-income nations are increasingly adopting High-Risk HPV DNA (hrHPV) testing as an adjunct to primary cytology screening, since epidemiologic studies have shown that this strategy may enhance screening effectiveness.1-8 Cervical cancer remains an important problem in Mexico despite a decades-old cytology program that in 2010 screened approximately eight million women.9 Recognizing the poor effectiveness of the Mexican cytology program, the government health insurance system for low-income citizens "Seguro Popular" recently introduced an alternative cervical cancer screening program (CCSP) based on hrHPV testing for affiliated women aged 35-64 years. The goal of the new CCSP is to achieve 85% coverage of six million women over a period of 5 years.

Objective. To compare the costs and number of unde- tected cases of four cervical cancer screening strategies (CCSS) in Mexico. Materials and methods. We estimated the costs and outcomes of the following CCSS: a) conventional Papanicolaou smear (Pap) alone; b) high-risk human papilloma virus testing (HR-HPV) as primary screening with Pap as reflex triage; c) HR-HPV as primary screening with HPV-16/18 typing, liquid-based cytology (LBC) and immunostaining for p16/Ki67 testing as reflex triage, and d) co-testing with HR-HPV and LBC with HPV-16/18 typing and immunostaining for p16/Ki67 as reflex triage. The outcome of interest was high-grade cervical lesions or cervical cancer. Results. HR-HPV testing, HPV typing, LBC testing and immunostaining is the best alternative because it is the least expensive option with an acceptable number of missed cases. Conclusions. The opportunity costs of a poor quality CCSS is many false negatives. Combining multiple tests may be a more cost-effective way to screen for cervical cancer in Mexico.