title: Accuracy of quantity-frequency and graduated frequency questionnaires in measuring alcohol intake: comparison with daily diary and commonly used laboratory markers.
abstract: OBJECTIVE
  To ascertain the accuracy of a quantity-frequency questionnaire (QF) and a graduated frequency questionnaire (GF) as methods of obtaining self-reported alcohol intake in relation to a daily diary and biochemical tests.
  
  
  METHODS
  QF and GF data were obtained before and after a 1-month daily diary on alcohol intake in a sample of 52 volunteers aged 20-63 years, of whom 43 were female. A blood sample to measure serum aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), gamma-glutamyltransferase (GGT) and % carbohydrate-deficient transferrin (CDT) was obtained at the outset.
  
  
  RESULTS
  Both QF and GF correlated closely with daily diary intake (r > 0.90). Compared with a daily diary, the mean QF intake was slightly lower, whereas the mean GF intake was 2-fold. The apparent overestimation by GF was independent of the actual consumption level. Self-reported alcohol intake by each method correlated closely with serum ASAT, ALAT and GGT (r = 0.41-0.67) but not with CDT.
  
  
  CONCLUSIONS
  In adults motivated to recall alcohol intake, both QF and GF classify individuals in the correct rank order, but GF probably overestimates actual alcohol consumption.
authors.affiliation: Finnish Foundation for Alcohol Studies, P O Box 220, FIN-00531 Helsinki, Finland.
authors.forename: Kari
authors.initials: K
authors.lastname: Poikolainen
authors.forename: Irina
authors.initials: I
authors.lastname: Podkletnova
authors.forename: Hannu
authors.initials: H
authors.lastname: Alho
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000097:blood / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D011939:Mental Recall; D008875:Middle Aged; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014342:Truth Disclosure