Imperial College London


Faculty of MedicineSchool of Public Health

Chair in Epidemiology and Public Health Medicine



+44 (0)20 7594 3328p.elliott Website




Miss Jennifer Wells +44 (0)20 7594 3328




154Norfolk PlaceSt Mary's Campus






BibTex format

author = {Greenwood, DC and Hardie, LJ and Frost, GS and Alwan, NA and Bradbury, KE and Carter, M and Elliott, P and Evans, CEL and Ford, HE and Hancock, N and Key, TJ and Liu, B and Morris, MA and Mulla, UZ and Petropoulou, K and Potter, GDM and Riboli, E and Young, H and Wark, PA and Cade, JE},
doi = {aje/kwz165},
journal = {American Journal of Epidemiology},
pages = {1858--1867},
title = {Validation of the Oxford WebQ Online 24-hour dietary questionnaire using biomarkers},
url = {},
volume = {188},
year = {2019}

RIS format (EndNote, RefMan)

AB - Oxford WebQ is an online dietary questionnaire covering 24 hours, appropriate for repeated administration in large-scale prospective studies including UK Biobank and the Million Women Study. We compared performance of the Oxford WebQ and a traditional interviewer-administered multi-pass 24-hour recall against biomarkers for protein, potassium and total sugar intake, and total energy expenditure estimated by accelerometry. 160 participants were recruited between 2014 and 2016 in London, UK, and measured at 3 non-consecutive time-points. The measurement error model simultaneously compared all 3 methods. Attenuation factors for protein, potassium, sugars and total energy intake estimated by the mean of 2 Oxford WebQs were 0.37, 0.42, 0.45, and 0.31 respectively, with performance improving incrementally for the mean of more measures. Correlation between the mean of 2 Oxford WebQs and estimated true intakes, reflecting attenuation when intake is categorised or ranked, was 0.47, 0.39, 0.40, and 0.38 respectively, also improving with repeated administration. These were similar to the more administratively burdensome interviewer-based recall. Using objective biomarkers as the standard, Oxford WebQ performs well across key nutrients in comparison with more administratively burdensome interviewer-based 24-hour recalls. Attenuation improves when the average is taken over repeated administration, reducing measurement error bias in assessment of diet-disease associations.
AU - Greenwood,DC
AU - Hardie,LJ
AU - Frost,GS
AU - Alwan,NA
AU - Bradbury,KE
AU - Carter,M
AU - Elliott,P
AU - Evans,CEL
AU - Ford,HE
AU - Hancock,N
AU - Key,TJ
AU - Liu,B
AU - Morris,MA
AU - Mulla,UZ
AU - Petropoulou,K
AU - Potter,GDM
AU - Riboli,E
AU - Young,H
AU - Wark,PA
AU - Cade,JE
DO - aje/kwz165
EP - 1867
PY - 2019///
SN - 1476-6256
SP - 1858
TI - Validation of the Oxford WebQ Online 24-hour dietary questionnaire using biomarkers
T2 - American Journal of Epidemiology
UR -
UR -
UR -
VL - 188
ER -