title: Use of the data system for field management of a clinical study conducted in Kolkata, India.
abstract: BACKGROUND
  Designing an appropriate data system is important to the success of a clinical study. However, little information is available on this topic. We share our experiences on designing, developing, and implementation of a data system for management of data and field activities of a complex clinical study.
  
  
  METHODS
  The data system was implemented aiming at determining the biological basis for the underperformance of oral vaccines, such as polio and rotavirus vaccines in children at a site in Kolkata, India. The system included several functionalities to control data and field activities. It was restricted to authorized users based on their access privileges. A relational database platform was chosen, and Microsoft Visual FoxPro 7.0 (Microsoft Corporation, Seattle, WA, USA) was used to develop the system. The system was installed at the clinic and data office to facilitate both the field and data management activities.
  
  
  RESULTS
  Data were doubly entered by two different data operators to identify keypunching errors in the data. Outliers, duplication, inconsistencies, missing entries, and linkage were also checked. Every modification and users log-in/log-out information was auto-recorded in an audit trail. The system offered tools for preparation of visit schedule of the participants. A visit considered as protocol deviation was documented by the system. The system alerted field staff to every upcoming visit date to organize the field activities and to inform participants which day to come. The system also produced a growth chart for evaluating nutritional status and referring the child to a specialized clinic if found to be severely malnourished.
  
  
  CONCLUSIONS
  The data system offered unique features for controlling for both data and field activities, which led to minimize drop-out rates as well as protocol deviations. Such system is warranted for a successful clinical study.
authors.affiliation: International Vaccine Institute, Seoul, South Korea. juyeon.park@ivi.int.
authors.forename: Ju Yeon
authors.initials: JY
authors.lastname: Park
authors.affiliation: International Vaccine Institute, Seoul, South Korea. drkim@ivi.int.
authors.forename: Deok Ryun
authors.initials: DR
authors.lastname: Kim
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India. bisakha7471@gmail.com.
authors.forename: Bisakha
authors.initials: B
authors.lastname: Haldar
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India. ahaque1234@gmail.com.
authors.forename: Aiyel Haque
authors.initials: AH
authors.lastname: Mallick
authors.affiliation: International Vaccine Institute, Seoul, South Korea. sakimhaji@gmail.com.
authors.forename: Soon Ae
authors.initials: SA
authors.lastname: Kim
authors.affiliation: International Vaccine Institute, Seoul, South Korea. adey@ivi.int.
authors.forename: Ayan
authors.initials: A
authors.lastname: Dey
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India. nandy_rk@hotmail.com.
authors.forename: Ranjan Kumar
authors.initials: RK
authors.lastname: Nandy
authors.affiliation: B.C. Roy Post Graduate Institute of Pediatric Sciences, Kolkata, India. dpaulpaed@rediffmail.com.
authors.forename: Dilip Kumar
authors.initials: DK
authors.lastname: Paul
authors.affiliation: B.C. Roy Post Graduate Institute of Pediatric Sciences, Kolkata, India. saugata.dr@gmail.com.
authors.forename: Saugata
authors.initials: S
authors.lastname: Choudhury
authors.affiliation: B.C. Roy Post Graduate Institute of Pediatric Sciences, Kolkata, India. sushamasahoo@gmail.com.
authors.forename: Shushama
authors.initials: S
authors.lastname: Sahoo
authors.affiliation: International Vaccine Institute, Seoul, South Korea. twierzba@path.org.|PATH, Washington, DC, USA. twierzba@path.org.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Wierzba
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India. dipikasur@hotmail.com.
authors.forename: Dipika
authors.initials: D
authors.lastname: Sur
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India. sumankanungo@gmail.com.
authors.forename: Suman
authors.initials: S
authors.lastname: Kanungo
authors.affiliation: International Vaccine Institute, Seoul, South Korea. mali25@jhu.edu.|Johns Hopkins Bloomberg School of Public Health, Baltimore, USA. mali25@jhu.edu.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ali
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India. mannab2000@yahoo.co.in.
authors.forename: Byomkesh
authors.initials: B
authors.lastname: Manna
mesh_terms: D000886:Anthropometry; D002648:Child; D054869:Clinical Audit; D000068456:Clinical Studies as Topic; D003628:Database Management Systems; D016208:Databases, Factual; D006801:Humans; D007194:India / Q000453:epidemiology; D015203:Reproducibility of Results; D058028:Research Report