Development and Validation of Food Frequency Questionnaire for Food and Nutrient Intake of Adults in Butajira, Southern Ethiopia.

Abstract

Background: To date, there is no culture-specific and validated Food Frequency Questionnaire (FFQ) available in Ethiopia. We developed a FFQ and evaluated its validity as compared to estimates of a food group and nutrient intakes derived from two 24-Hour Dietary Recalls (24-HRs).Method: A total of 105 adults, of which 43 (41%) were men and 62 (59%) women aged 20-65 years participated in this study. To evaluate the validity of FFQ against two 24-HRs, we used a paired t-test and Wilcoxon- signed rank test to compare mean and median daily nutrient and food intakes obtained from the averages of the two 24-HRs and the FFQ, correlation coefficients to measure the strength and direction of the correlation, Cross-classification and kappa to assess classification agreement and Bland-Altman analysis for assessing limits of agreement between the two methods.Results: Mean energy and macronutrient intakes obtained from the FFQ were significantly higher than those obtained from the mean of two 24-HRs. For energy and macronutrients, the crude correlation between two instruments ranged from 0.05 (total fat) to 0.32 (carbohydrate). Whereas, for micronutrients, it ranged from 0.1 (calcium) to 0.49 (vitamin B1). The de-attenuated correlation ranged from to 0.10 (total fat) to 0.80 (vitamin A) Visual inspection of the Bland-Altman plots for both energy and macronutrients shows no consistent trend across the intake values. For the majority of the food groups, no significant difference was observed in median intake of foods and nutrients between 24-HRs and FFQ. Crude correlation for food groups ranged from 0.12 (egg) to 0.78 (legumes). The de-attenuated correlation ranged from 0.24 (egg) to 0.10 (Meat/Poultry/Fish). The FFQ showed a fair classification agreement with the 24-HRs for cereals, legumes, and roots and tubers intakes. A systematic trend of overestimation for roots and tubers and under estimation of beverage intakes at higher values was observed when we used FFQ.Conclusion: The FFQ is valid to assess and rank individuals in terms of intakes of most food groups according to high and low intake categories. Individual level validity was acceptable for energy and most nutrients as indicated by de-attenuated correlation coefficients and Bland-Altman plots. However, group level validity was poor for most nutrients.