%0 Journal Article
%@ 2369-2960
%I JMIR Publications
%V 7
%N 1
%P e24588
%T Toward a Working Definition of eCohort Studies in Health Research: Narrative Literature Review
%A Nittas,Vasileios
%A Puhan,Milo Alan
%A von Wyl,Viktor
%+ Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Hirschengraben 84, Zurich, 8001, Switzerland, 41 44 63 44946, vasileios.nittas@uzh.ch
%K cohorts
%K digital epidemiology
%K eCohorts
%K eHealth
%D 2021
%7 21.1.2021
%9 Original Paper
%J JMIR Public Health Surveill
%G English
%X Background: The wide availability of internet-connected devices and new sensor technologies increasingly infuse longitudinal observational study designs and cohort studies. Simultaneously, the costly and time-consuming nature of traditional cohorts has given rise to alternative, technology-driven designs such as eCohorts, which remain inadequately described in the scientific literature. Objective: The aim of this study was to outline and discuss what may constitute an eCohort, as well as to formulate a first working definition for health researchers based on a review of the relevant literature. Methods: A two-staged review and synthesis process was performed comparing 10 traditional cohorts and 10 eCohorts across the six core steps in the life cycle of cohort designs. Results: eCohorts are a novel type of technology-driven cohort study that are not physically linked to a clinical setting, follow more relaxed and not necessarily random sampling procedures, are primarily based on self-reported and digitally collected data, and systematically aim to leverage the internet and digitalization to achieve flexibility, interactivity, patient-centeredness, and scalability. This approach comes with some hurdles such as data quality, generalizability, and privacy concerns. Conclusions: eCohorts have similarities to their traditional counterparts; however, they are sufficiently distinct to be treated as a separate type of cohort design. The novelty of eCohorts is associated with a range of strengths and weaknesses that require further exploration. 
%M 33475521
%R 10.2196/24588
%U http://publichealth.jmir.org/2021/1/e24588/
%U https://doi.org/10.2196/24588
%U http://www.ncbi.nlm.nih.gov/pubmed/33475521