title: Development and evaluation of the Oxford WebQ, a low-cost, web-based method for assessment of previous 24 h dietary intakes in large-scale prospective studies.
abstract: OBJECTIVE
  To describe the development of the Oxford WebQ, a web-based 24 h dietary assessment tool developed for repeated administration in large prospective studies; and to report the preliminary assessment of its performance for estimating nutrient intakes.
  
  
  METHODS
  We developed the Oxford WebQ by repeated testing until it was sufficiently comprehensive and easy to use. For the latest version, we compared nutrient intakes from volunteers who completed both the Oxford WebQ and an interviewer-administered 24 h dietary recall on the same day.
  
  
  METHODS
  Oxford, UK.
  
  
  METHODS
  A total of 116 men and women.
  
  
  RESULTS
  The WebQ took a median of 12·5 (interquartile range: 10·8-16·3) min to self-complete and nutrient intakes were estimated automatically. By contrast, the interviewer-administered 24 h dietary recall took 30 min to complete and 30 min to code. Compared with the 24 h dietary recall, the mean Spearman's correlation for the 21 nutrients obtained from the WebQ was 0·6, with the majority between 0·5 and 0·9. The mean differences in intake were less than ±10 % for all nutrients except for carotene and vitamins B12 and D. On rare occasions a food item was reported in only one assessment method, but this was not more frequent or systematically different between the methods.
  
  
  CONCLUSIONS
  Compared with an interviewer-based 24 h dietary recall, the WebQ captures similar food items and estimates similar nutrient intakes for a single day's dietary intake. The WebQ is self-administered and nutrients are estimated automatically, providing a low-cost method for measuring dietary intake in large-scale studies.
authors: Cancer Epidemiology Unit, Nuffield Department of Clinical Medicine, University of Oxford, Richard Doll Building, Roosevelt Drive, Oxford OX3 7LF, UK.
authors: Bette
authors: B
authors: Liu
authors: Heather
authors: H
authors: Young
authors: Francesca L
authors: FL
authors: Crowe
authors: Victoria S
authors: VS
authors: Benson
authors: Elizabeth A
authors: EA
authors: Spencer
authors: Timothy J
authors: TJ
authors: Key
authors: Paul N
authors: PN
authors: Appleby
authors: Valerie
authors: V
authors: Beral
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004032:Diet; D015930:Diet Records; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D006801:Humans; D020407:Internet; D007407:Interviews as Topic; D008297:Male; D018977:Micronutrients / Q000008:administration & dosage; D008875:Middle Aged; D015596:Nutrition Assessment; D011446:Prospective Studies; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D006113:United Kingdom; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D004044:Dietary Proteins; D018977:Micronutrients