Validation of a quantitative food-frequency questionnaire for use in Western Mali.

OBJECTIVE The purpose of this study was to validate a quantitative food-frequency questionnaire (QFFQ) created for assessing the usual intake of foods and nutrients in the prevailing season in Western Mali. DESIGN Intake of foods and nutrients over the week preceding the interview was measured with a 69-item QFFQ. Intakes were compared with intakes as measured with 2-day combined weighed and recalled diet records. SETTING A rural village in Western Mali, West Africa. SUBJECTS Twenty-seven men and 48 women (15-59 years of age) representing 18 households. RESULTS Spearman rank correlations between intake of food groups from the QFFQ and the diet record ranged from 0.09 (meat/fish) to 0.58 (tea/coffee). Median coefficient was 0.37. Median Spearman correlation coefficient for nutrient intake was 0.40. Men had higher median correlation coefficients than did women. The proportion of subjects being classified into the same quartile of food intake was on median 33%, while a median of 7% was misclassified into extreme quartiles. Correct classification into the same quartile for intake of nutrients was on median 34% while a median of 4% was grossly misclassified. Intakes of most food groups and nutrients as measured by the QFFQ were higher than those measured by the diet records. However, while men had higher estimated intakes for foods eaten in-between meals, women in general had higher intake of foods eaten in the main meals. CONCLUSION This QFFQ can be used for comparing the intake of foods and nutrients between groups within this study population. It therefore represents a useful tool in the surveillance of food intake in the population, both in identifying vulnerable groups and for tracking food intake over time. The differences between men and women in overestimating food intake need to be taken into account when using the method.