Comparison of telephone vs face-to-face interviews in the assessment of dietary intake by the 24 h recall EPIC SOFT program--the Norwegian calibration study.

OBJECTIVE: To compare food group intakes in grams, total energy and energy contribution from macronutrients between two random samples of women, using a standardized computer program (EPIC SOFT) with either a face-to-face or a telephone 24 h recall interview design.
METHODS: Two groups of Norwegian women living in Tromsø were drawn at random from the Norwegian Women and Cancer Study (NOWAC) cohort. The EPIC SOFT computer program was used to conduct single 24 h dietary recalls either by telephone or face to face. For the latter, 160 women were invited, of whom 111 responded positively (crude response rate=69.4%) and 102 were interviewed. For the telephone option, 180 were invited to participate, 109 responded positively (crude response rate=60.6%) and 103 were interviewed.
RESULTS: The two groups of women were similar with respect to age, body mass index, basal metabolic rate, smoking, education, physical activity and special diet status. No statistically significant difference in dietary intake was found between interviews conducted by telephone and face-to-face, except for 'egg and egg products' (P<0.01), for which intake was higher in the telephone group. Total energy intake differed, but the difference was attributable to one interviewer. The distribution of energy-contributing nutrients was not significantly different between groups, except for reported energy percentage from protein (P=0.02), which was significantly higher in the face-to-face group.
CONCLUSION: The telephone vs face-to-face interview design did not influence recalled diet when using the EPIC SOFT program.