title: How reliable is internet-based self-reported identity, socio-demographic and obesity measures in European adults?
abstract: In e-health intervention studies, there are concerns about the reliability of internet-based, self-reported (SR) data and about the potential for identity fraud. This study introduced and tested a novel procedure for assessing the validity of internet-based, SR identity and validated anthropometric and demographic data via measurements performed face-to-face in a validation study (VS). Participants (n = 140) from seven European countries, participating in the Food4Me intervention study which aimed to test the efficacy of personalised nutrition approaches delivered via the internet, were invited to take part in the VS. Participants visited a research centre in each country within 2 weeks of providing SR data via the internet. Participants received detailed instructions on how to perform each measurement. Individual's identity was checked visually and by repeated collection and analysis of buccal cell DNA for 33 genetic variants. Validation of identity using genomic information showed perfect concordance between SR and VS. Similar results were found for demographic data (age and sex verification). We observed strong intra-class correlation coefficients between SR and VS for anthropometric data (height 0.990, weight 0.994 and BMI 0.983). However, internet-based SR weight was under-reported (Δ -0.70 kg [-3.6 to 2.1], p < 0.0001) and, therefore, BMI was lower for SR data (Δ -0.29 kg m(-2) [-1.5 to 1.0], p < 0.0001). BMI classification was correct in 93 % of cases. We demonstrate the utility of genotype information for detection of possible identity fraud in e-health studies and confirm the reliability of internet-based, SR anthropometric and demographic data collected in the Food4Me study.
  
  
  BACKGROUND
  NCT01530139 ( http://clinicaltrials.gov/show/NCT01530139 ).
authors.affiliation: Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL UK.
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authors.affiliation: Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL UK.
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authors.affiliation: UCD Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Republic of Ireland.
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authors.affiliation: UCD Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Republic of Ireland.
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authors.affiliation: UCD Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Republic of Ireland.
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authors.affiliation: Hugh Sinclair Unit of Human Nutrition and Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK.
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authors.affiliation: Hugh Sinclair Unit of Human Nutrition and Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK.
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authors.affiliation: Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands.
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authors.affiliation: Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
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authors.affiliation: Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
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authors.affiliation: Department of Nutrition, Food Science and Physiology, University of Navarra, Pamplona, Spain.|CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.
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authors.affiliation: Department of Nutrition, Food Science and Physiology, University of Navarra, Pamplona, Spain.
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authors.affiliation: ZIEL Research Center of Nutrition and Food Sciences, Biochemistry Unit, Technische Universität München, Munich, Germany.
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authors.affiliation: ZIEL Research Center of Nutrition and Food Sciences, Biochemistry Unit, Technische Universität München, Munich, Germany.
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authors.affiliation: ZIEL Research Center of Nutrition and Food Sciences, Biochemistry Unit, Technische Universität München, Munich, Germany.
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authors.initials: LD
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authors.affiliation: Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
authors.forename: Yannis
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authors.affiliation: National Food & Nutrition Institute (IZZ), Warsaw, Poland.
authors.forename: Iwona
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authors.affiliation: UCD Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Republic of Ireland.
authors.forename: Eileen R
authors.initials: ER
authors.lastname: Gibney
authors.affiliation: UCD Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Republic of Ireland.
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authors.affiliation: UCD Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Republic of Ireland.
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authors.affiliation: Hugh Sinclair Unit of Human Nutrition and Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK.
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authors.affiliation: Department of Nutrition, Food Science and Physiology, University of Navarra, Pamplona, Spain.|CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: J Alfredo
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authors.affiliation: ZIEL Research Center of Nutrition and Food Sciences, Biochemistry Unit, Technische Universität München, Munich, Germany.
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authors.affiliation: Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands.
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authors.affiliation: UCD Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Republic of Ireland.
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authors.affiliation: Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL UK.
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