The Anyang Esophageal Cancer Cohort Study: Study Design, Implementation of Fieldwork, and Use of Computer-Aided Survey System

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. Methodology/Principal Findings: 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/Significance: 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 simila

Three-level infrastructure of the AECCS.

<p>This figure illustrates how three tiers of responsibility are integrated in the fieldwork infrastructure for optimal interaction with the target population in the Anyang Esophageal Cancer Cohort Study, Anyang, China, 2006-present. There are a total of nine village committees in the third tier of the infrastructure.</p

Number of participants and response proportions in the baseline investigation, Anyang Esophageal Cancer Cohort Study (2006–2009).

†<p>Examination of palmar skin and penis was limited to 6 villages (Hengcun, Malan, Tunzhuang, Xiaopu, Xitaoyuan, and Zhuzhao) in the baseline investigation.</p>‡<p>Fifty women with previous hysterectomies did not have a cervical examination.</p

Selected characteristics of endoscopy participants in the baseline investigation, Anyang Esophageal Cancer Cohort Study (2006–2009).

<p>Selected characteristics of endoscopy participants in the baseline investigation, Anyang Esophageal Cancer Cohort Study (2006–2009).</p

Computer-aided survey system (CASS) with client/server mode using a WLAN.

<p>The hosting system for the database resides on the server. The staff in each examination room can synchronously enter data in the database by logging into client application software installed on client computers using a wireless local area network (WLAN). After registration, blood is drawn. Eligible participants with no communicable blood diseases then continue on and participate in an interview and examination of the oral cavity, palmar skin, cervix/penis and esophagus.</p