The relative validity of vitamin intakes derived from a food frequency questionnaire compared to 24-hour recalls and biological measurements: results from the EPIC pilot study in Germany. European Prospective Investigation into Cancer and Nutrition.

Background: For the European Prospective Investigation into Cancer and Nutrition (EPIC) study Germany, a self-administered food frequency questionnaire (FFQ) was developed and tested for its relative validity and reproducibility in 1991/1992. Study participants were 92 potential cohort members. This paper reports results regarding retinol, carotenoids, tocopherols and ascorbic acid.

Reproducibility and relative validity of energy and macronutrient intake of a food frequency questionnaire developed for the German part of the EPIC project. European Prospective Investigation into Cancer and Nutrition.

Background: For use in the German part of the European Prospective Investigation into Cancer and Nutrition (EPIC) a self-administered, optically readable food frequency questionnaire (FFQ) was developed to assess individuals' usual food and nutrient intake over the past year. The food list comprised 158 food items for which the typical portion size, the consumption frequency (1-6 times) and the time period (day, week, month, or year) were requested. This paper reports the results of the reproducibility and relative validity of nutrient intakes obtained by this instrument.

Reproducibility and relative validity of food group intake in a food frequency questionnaire developed for the German part of the EPIC project. European Prospective Investigation into Cancer and Nutrition.

Background: For the German part of the European Prospective Investigation into Cancer and Nutrition (EPIC), a self-administered, optically-readable food frequency questionnaire (FFQ), including 158 food items and 87 coloured portion size photographs, was developed to assess the usual food and nutrient intake of individuals during the past year. In 1991/1992, the reproducibility and validity of the questionnaire measurements were studied according to the EPIC protocol. This article reports the results on reproducibility and relative validity of measurement of food group intake.