Accuracy of quantity-frequency and graduated frequency questionnaires in measuring alcohol intake: comparison with daily diary and commonly used laboratory markers.
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.
Poikolainen
Kari
K
Finnish Foundation for Alcohol Studies, P O Box 220, FIN-00531 Helsinki, Finland.
Podkletnova
Irina
I
Alho
Hannu
H
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