Objective: Development and validation of a short instrument to assess the dietary intake of heterocyclic aromatic amines (HCA).
Design: At first, a longer instrument asking for the consumption of 11 meat and fish items and different preparation methods was developed. The degree of browning of these foods was assessed by means of photos. This questionnaire was sent to 500 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) in Heidelberg, Germany, in June 1999. Using 385 completed questionnaires, a short questionnaire was developed covering just seven food items, which was sent to the participants again. Of these, 344 were returned within four months. Total dietary intake of HCA as well as the intake of different HCA were calculated and compared between both versions.
Results: Median dietary intake of total HCA was 103 ng day-1 as assessed with the short version; the intakes of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx) were 63, 34 and 2 ng day-1, respectively. These results did not differ significantly from those obtained with the longer version. Spearman rank correlation coefficients between the long and the short version ranged from 0.46 to 0.6. In quartile cross-classification, 70-78% of the participants were assigned into the same or an adjacent quartile while categorisation into opposite quartiles was < or =3.5%.
Conclusion: The short version of the HCA questionnaire demonstrates good validity compared with the longer version. The intake of HCA as assessed with the short questionnaire is comparable to that found in other studies using a short questionnaire.