title: The Anyang Esophageal Cancer Cohort Study: study design, implementation of fieldwork, and use of computer-aided survey system.
abstract: BACKGROUND
  Human papillomavirus (HPV) has been observed repeatedly in esophageal squamous cell carcinoma (ESCC) tissues. However, the causal relationship between HPV infection and the onset of ESCC remains unknown. A large cohort study focusing on this topic is being carried out in rural Anyang, China.
  
  
  RESULTS
  The Anyang Esophageal Cancer Cohort Study (AECCS) is a population-based prospective endoscopic cohort study designed to investigate the association of HPV infection and ESCC. This paper provides information regarding the design and implementation of this study. In particular we describe the recruitment strategies and quality control procedures which have been put into place, and the custom designed computer-aided survey system (CASS) used for this project. This system integrates barcode technology and unique identification numbers, and has been developed to facilitate real-time data management throughout the workflow using a wireless local area network. A total of 8,112 (75.3%) of invited subjects participated in the baseline endoscopic examination; of those invited two years later to take part in the first cycle of follow-up, 91.9% have complied.
  
  
  CONCLUSIONS
  The AECCS study has high potential for evaluating the causal relationship between HPV infection and the occurrence of ESCC. The experience in setting up the AECCS may be beneficial for others planning to initiate similar epidemiological studies in developing countries.
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Liu
authors.forename: Fangcen
authors.initials: F
authors.lastname: Guo
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhou
authors.forename: Zhonghu
authors.initials: Z
authors.lastname: He
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Tian
authors.forename: Chuanhai
authors.initials: C
authors.lastname: Guo
authors.forename: Tao
authors.initials: T
authors.lastname: Ning
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Pan
authors.forename: Hong
authors.initials: H
authors.lastname: Cai
authors.forename: Yang
authors.initials: Y
authors.lastname: Ke
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000821:virology*; D002478:Cells, Cultured; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D004938:Esophageal Neoplasms / Q000453:epidemiology* / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D027383:Papillomaviridae / Q000472:pathogenicity*; D030361:Papillomavirus Infections / Q000453:epidemiology*; D016133:Polymerase Chain Reaction; D011446:Prospective Studies