title: Internet-Based Birth-Cohort Studies: Is This the Future for Epidemiology?
abstract: BACKGROUND
  International collaborative cohorts the NINFEA and the ELF studies are mother-child cohorts that use the internet for recruitment and follow-up of their members. The cohorts investigated the association of early life exposures and a wide range of non-communicable diseases.
  
  
  OBJECTIVE
  The objective is to report the research methodology, with emphasis on the advantages and limitations offered by an Internet-based design. These studies were conducted in Turin, Italy and Wellington, New Zealand.
  
  
  METHODS
  The cohorts utilized various online/offline methods to recruit participants. Pregnant women who became aware volunteered, completed an online questionnaire, thus obtaining baseline information.
  
  
  RESULTS
  The NINFEA study has recruited 7003 pregnant women, while the ELF study has recruited 2197 women. The cohorts targeted the whole country, utilizing a range of support processes to reduce the attrition rate of the participants. For the NINFEA and ELF cohorts, online participants were predominantly older (35% and 28.9%, respectively), highly educated (55.6% and 84.9%, respectively), and were in their final trimester of pregnancy (48.5% and 53.6%, respectively).
  
  
  CONCLUSIONS
  Internet-based cohort epidemiological studies are feasible, however, it is clear that participants are self-selective samples, as is the case for many birth cohorts. Internet-based cohort studies are potentially cost-effective and novel methodology for conducting long-term epidemiology research. However, from our experience, participants tend to be self-selective. In marked time, if the cohorts are to form part of a larger research program they require further use and exploration to address biases and overcome limitations.
authors.affiliation: Centre for Public Health Research, Massey University, Wellington, New Zealand. r.t.firestone@massey.ac.nz.
authors.forename: Ridvan
authors.identifier: http://orcid.org/0000-0003-2834-8044
authors.initials: R
authors.lastname: Firestone
authors.forename: Soo
authors.identifier: http://orcid.org/0000-0002-6438-8329
authors.initials: S
authors.lastname: Cheng
authors.forename: Neil
authors.identifier: http://orcid.org/0000-0002-9938-7852
authors.initials: N
authors.lastname: Pearce
authors.forename: Jeroen
authors.identifier: http://orcid.org/0000-0003-3599-4036
authors.initials: J
authors.lastname: Douwes
authors.forename: Franco
authors.identifier: http://orcid.org/0000-0001-8846-7454
authors.initials: F
authors.lastname: Merletti
authors.forename: Costanza
authors.identifier: http://orcid.org/0000-0002-4519-2822
authors.initials: C
authors.lastname: Pizzi
authors.forename: Emanuele
authors.identifier: http://orcid.org/0000-0003-1446-1169
authors.initials: E
authors.lastname: Pivetta
authors.forename: Franca
authors.identifier: http://orcid.org/0000-0002-9544-6472
authors.initials: F
authors.lastname: Rusconi
authors.forename: Lorenzo
authors.identifier: http://orcid.org/0000-0003-0316-9402
authors.initials: L
authors.lastname: Richiardi
keywords: Internet; birth cohort; epidemiology