title: Triage strategies in cervical cancer detection in Mexico: methods of the FRIDA Study.
abstract: OBJECTIVE
  This paper describes the study design and baseline characteristics of the study population, including the first 30 829 women who enrolled in the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage (FRIDA Study). This is a large population based study that is evaluating the performance and cost-effectiveness of different triage strategies for high-risk HPV (hrHPV) positive women in Mexico.
  
  
  METHODS
  The target population is more than 100 000 women aged 30 to 64 years who attend the Cervical Cancer Screening Program in 100 health centers in the state of Tlaxcala, Mexico. Since August 2013, all women in the region have been invited to enroll in the study. The study participants are evaluated to determine hrHPV infection using the Cobas 4800 HPV test. The HPV-16/18 genotyping and cytology triage strategies are performed as reflex tests in all hrHPV-positive participants. Women with a positive HPV-16/18 test and/or abnormal cytology (atypical squamous cells of undetermined significance or worse, ASCUS+) are referred for colposcopy evaluation, where a minimum of four biopsies and an endocervical sample are systematically collected. Histologic confirmation is performed by a standardized panel of pathologists.
  
  
  RESULTS
  Among the 30 829 women who have been screened, the overall prevalence of hrHPV is 11.0%. The overall prevalence of HPV16 and HPV18 are 1.5% and 0.7%, respectively. Cytological abnormalities (ASCUS+) were detected in 11.8% of the hrHPV-positive women. A total of 27.0% (920/3,401) of the hrHPV-positive women were referred to colposcopy because of a positive HPV16/18 test and/or abnormal reflex cytology, (31.6% had only ASCUS+, 53.6% were HPV16/18 positive with a normal cytology result, and 9.5% were positive to both triage tests).
  
  
  CONCLUSIONS
  The results of this study will help policy makers and health service providers establish the best practices for triage in cervical cancer screening in Mexico and other countries.
authors.forename: Leticia
authors.initials: L
authors.lastname: Torres-Ibarra
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lazcano-Ponce
authors.forename: Eduardo L
authors.initials: EL
authors.lastname: Franco
authors.forename: Jack
authors.initials: J
authors.lastname: Cuzick
authors.forename: Mauricio
authors.initials: M
authors.lastname: Hernández-Ávila
authors.forename: Attila
authors.initials: A
authors.lastname: Lorincz
authors.forename: Berenice
authors.initials: B
authors.lastname: Rivera
authors.forename: Paula
authors.initials: P
authors.lastname: Ramírez
authors.forename: Indira
authors.initials: I
authors.lastname: Mendiola-Pastrana
authors.forename: Samantha E
authors.initials: SE
authors.lastname: Rudolph
authors.forename: Leith
authors.initials: L
authors.lastname: León-Maldonado
authors.forename: Rubí
authors.initials: R
authors.lastname: Hernández
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrios
authors.forename: Patti
authors.initials: P
authors.lastname: Gravitt
authors.forename: Anna Barbara
authors.initials: AB
authors.lastname: Moscicki
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Schmeler
authors.forename: Yvonne N
authors.initials: YN
authors.lastname: Flores
authors.forename: Pablo
authors.initials: P
authors.lastname: Méndez-Hernández
authors.forename: Jorge
authors.initials: J
authors.lastname: Salmerón
mesh_terms: D000328:Adult; D065309:Atypical Squamous Cells of the Cervix / Q000473:pathology / Q000821:virology; D001706:Biopsy; D003127:Colposcopy; D055088:Early Detection of Cancer / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D052162:Human papillomavirus 16 / Q000302:isolation & purification; D052161:Human papillomavirus 18 / Q000302:isolation & purification; D006801:Humans; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000453:epidemiology*; D015995:Prevalence; D011314:Preventive Health Services / Q000379:methods / Q000458:organization & administration*; D012306:Risk; D014218:Triage / Q000379:methods* / Q000458:organization & administration; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology