Validation of a food frequency questionnaire for food and nutrient intake of adults in Butajira, Southern Ethiopia.

Background: Food frequency questionnaires (FFQ) is the most commonly used dietary assessment tool in epidemiological studies, due to ease of administration and feasibility. However, the information collected by FFQ is associated with lower accuracy. For accurate interpretation of the food frequency results that arise from epidemiological studies, it needs to be compared with a more accurate dietary assessment method. To date, there is no culture-specific and validated FFQ available in Ethiopia. Objective: This study aims to evaluate the validatiy of a locally developed FFQ for estimating food and nutrient intakes of adults in Butajira, southern Ethiopia. Methodology: We employed a community-based cross-sectional study and included a total of one hundred fifteen adults aged 20-65 years. FFQ was developed using two sources of data; focus group discussion and previous two days 24-Hour diet recall. The relative validity of the FFQ was assessed against the average of two interactive 24-hour dietary recalls. Intakes of macronutrients (energy, protein, carbohydrate, fat), micro-nutrients (calcium, iron, vitamin, vitamin B1, vitamin B2) and food groups were measured by the two methods. The validity of the FFQ was evaluated by comparing estimates of specific nutrients and food groups derived from the FFQ against the 24-hour dietary recalls by calculating the mean or median difference, correlation coefficients, cross-classification, and Bland Altman test. Result: Mean energy and macronutrient intakes obtained from the FFQ were significantly higher than those obtained from the mean of 24-hour dietary recalls. The correlation between energy and macro-nutrients measured by the two methods varies from 0.05 (Total fat) to 0.32 (carbohydrate) and from 0.1(calcium) to 0.49 (vitamin B1) for micronutrients. FFQ did not adequately classify subjects with respect to energy, macro-nutrients and most of the micro-nutrients. A systematic mean difference was observed in vitamin A and iron intake in the bland–Altman agreement test. For ...