%0 Journal Article
%@ 1438-8871
%I JMIR Publications Inc.
%V 17
%N 4
%P e96
%T Validity of Internet-Based Longitudinal Study Data: The Elephant in the Virtual Room
%A Pugh,Carys A
%A Summers,Kim M
%A Bronsvoort,B Mark C
%A Handel,Ian G
%A Clements,Dylan N
%+ The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, EH25 9RG, United Kingdom, 44 1316519167, Carys.Pugh@roslin.ed.ac.uk
%K epidemiology
%K validation studies as topic
%K Internet
%K questionnaires
%K longitudinal studies
%K health
%K canine
%D 2015
%7 16.04.2015
%9 Viewpoint
%J J Med Internet Res
%G English
%X Background: Internet-based data collection relies on well-designed and validated questionnaires. The theory behind designing and validating questionnaires is well described, but few practical examples of how to approach validation are available in the literature. Objective: We aimed to validate data collected in an ongoing Internet-based longitudinal health study through direct visits to participants and recall of their health records. We demonstrate that despite extensive pre-planning, social desirability can still affect data in unexpected ways and that anticipation of poor quality data may be confounded by positive validation. Methods: Dogslife is a large-scale, Web-based longitudinal study of canine health, in which owners of Labrador Retrievers were recruited and questioned at regular intervals about the lifestyle and health of their dogs using an Internet-based questionnaire. The Dogslife questionnaire predominantly consists of closed-answer questions. In our work, two separate validation methodologies were used: (1) direct interviews with 43 participants during visits to their households and (2) comparison of owner-entered health reports with 139 historical health records. Results: Our results indicate that user-derived measures should not be regarded as a single category; instead, each measurement should be considered separately as each presents its own challenge to participants. We recommend trying to ascertain the extent of recall decay within a study and, if necessary, using this to guide data collection timepoints and analyses. Finally, we recommend that multiple methods of communication facilitate validation studies and aid cohort engagement. Conclusions: Our study highlighted how the theory underpinning online questionnaire design and validation translates into practical data issues when applied to Internet-based studies. Validation should be regarded as an extension of questionnaire design, and that validation work should commence as soon as sufficient data are available. We believe that validation is a crucial step and hope our suggested guidelines will help facilitate validation of other Internet-based cohort studies. 
%M 25887101
%R 10.2196/jmir.3530
%U http://www.jmir.org/2015/4/e96/
%U https://doi.org/10.2196/jmir.3530
%U http://www.ncbi.nlm.nih.gov/pubmed/25887101