Assessing dietary diversity in pregnant women: Relative validity of the list-based and open recall methods

Abstract

Background: The Minimum Dietary Diversity for Women (MMD-W) was validated as a proxy of micronutrient adequacy for nonpregnant women, with proposed data collection being either a list-based or a qualitative open recall method. Few studies have compared the performance of these 2 methods. Objectives: We compared performance in predicting micronutrient adequacy of food group indicators (FGIs) measured by the list-based and the quantitative open recall methods using varying quantity cut-offs. We also examined the agreement between list-based and open recall FGIs. Methods: Data were collected in Bangladesh (n = 600 pregnant women) and India (n = 655). The performance of different indicators to predict micronutrient adequacy was compared using receiver operating characteristic (ROC) analysis. Correlations between list-based and open recall FGIs were calculated using Spearman's rank test; agreement was assessed by the intraclass correlation coefficient (ICC) and kappa statistics. Food groups that were most often misreported by the list-based method were identified. Results: There were no statistically significant differences in ROC curves between list-based and open recall FGIs in either country. In Bangladesh, correlations between list-based and open recall FGIs varied between 0.6 and 0.8; ICC values were 0.43-0.75; kappa values were 0.51-0.53 when using a cut-off of any quantity or 15 g for open recall, but were lower (k = 0.24) with the cut-off of 1 portion. In India, these values were lower: ∼0.4 for correlation, 0.32-0.37 for ICCs, and 0.17-0.22 for kappas. Food groups most susceptible to misreporting using the list-based method were beans/peas in Bangladesh and other vegetables in India. Conclusions: Our study provides initial support for the use of list-based questionnaires in assessing food group diversity or prevalence of MDD-W in pregnant women. Additional and context-specific work may be required to understand the potential of simple methodologies to assess consumption of specific food groups. This trial was registered at clinicaltrials.gov as NCT02745249 (Bangladesh) and NCT03378141 (India).