Validation of the European Prospective Investigation into Cancer (EPIC) Food Frequency Questionnaire for use among Adults in Lebanon.

Abstract

OBJECTIVE: To validate the EPIC food frequency questionnaire (FFQ) in Lebanon. DESIGN: Validation of the EPIC FFQ was done against three 24-hour recalls. Unadjusted and energy adjusted correlations, Bland Altman plots, and weighed kappa statistics were used to assess the agreement between the two methods. SETTING: Lebanon. PARTICIPANTS: 119 adults (staff and students) at a Lebanese University. RESULTS: Good unadjusted and energy-adjusted correlation coefficients were found between data from the two methods which ranged from -0.002 (vitamin A) to 0.337 (carbohydrates) and were all statistically significant except for vitamin D, vitamin E, vitamin A, selenium, and niacin. Slight/fair agreement was reported through weighed kappa estimates for unadjusted data ranging from -0.05 (vitamin C) to 0.248 (magnesium) and for energy-adjusted data ranging from -0.034 (vitamin A) to 0.203 (phosphorus). Individuals were categorised into exact and adjacent quartiles with an average of 78% for unadjusted data and 70% for energy-adjusted data, indicating a very good agreement between the EPIC FFQ and the average of the 24-HRs data. The visual inspection of the Bland-Altman plots revealed an over-estimation of energy, carbohydrates, protein, and fat intakes by the FFQ method. CONCLUSION: Overall, when all tests were taken into consideration, this study demonstrated an acceptable agreement of the EPIC FFQ with the 24-hour dietary recall method and significantly good correlations between dietary intakes. Therefore, the EPIC FFQ can be considered a valid tool for assessing diet in epidemiological studies among Lebanese adults.