Respondents' evaluation of the 24-h dietary recall method (EPIC-Soft) in the EFCOVAL Project

To improve participation rate, accuracy and respondents' compliance, it is important to know the respondents' viewpoint.

To evaluate respondents' preferences and perception about the EPIC-Soft (the software developed to conduct 24-h dietary recalls (24-HDRs) in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study) 24-HDR interviews and to compare these preferences and perception between population groups (for example, between genders).

Data were collected in Belgium, Czech Republic, France, the Netherlands and Norway in 2007. Two 24-HDRs (face-to-face and telephone administered) were conducted using EPIC-Soft. An evaluation questionnaire on different study aspects was completed by the respondents.

Data were collected in the European Food Consumption Validation Study.

A convenience sample of 600 apparently healthy men and women, 45-65 years old and including all educational levels, were recruited (120 subjects per country). Differences among population groups were compared by means of the χ (2)-test.

A total of 585 respondents completed the evaluation questionnaire. In all, 88% experienced problems only to a low degree when answering face-to-face and telephone-administered 24-HDR using EPIC-Soft. A total of 15% would have preferred help of another person during the face-to-face interview in the study center (mainly men: P < 0.001). Significantly, more subjects in the Netherlands and in Norway preferred two telephone (instead of face-to-face) interviews compared with the other countries (P<0.001).

Most subjects only experienced problems to a low degree during the EPIC-Soft interviews. Differences in preferences and capabilities to answer the EPIC-Soft interviews were identified between population groups (for example, gender differences). Therefore, the methods and the design to be used in a survey should be adapted according to the study population, so as to optimize response rate and compliance.