Minimum Dietary Diversity for Women: Partitioning Misclassifications by Proxy Data Collection Methods using Weighed Food Records as the Reference in Ethiopia

Background: Nonquantitative list-based or open 24-h recalls (24-HRs) have been shown to overestimate the prevalence of Minimum Dietary Diversity for Women (MDD-W), as compared with direct quantitative observations. However, the main sources of error are unknown. Objectives: To assess the measurement agreement of proxy data collection methods for MDD-W, as compared with weighed food records (WFRs). Methods: Applying a noninferiority design, data were collected from 431 nonpregnant females in Ethiopia. MDD-W estimates from both proxy data collection methods were compared with the WFR prevalence by McNemar’s chi-square tests, Cohen’s Kappa, and receiver operator characteristic analyses. Ten-point food group diversity scores (FGDS) were compared by Bland–Altman plots, Wilcoxon matched-pairs tests, and weighted Kappa. Food group misclassifications were partitioned into errors related to respondent biases or the questionnaire development. Results: List-based and open 24-HRs overreported MDD-W by 8 and 4 percentage points, respectively, as compared with WFR (objective MDD-W prevalence: 8%). Furthermore, list-based 24-HRs overestimated FGDS by 0.4 points (limits of agreement [LOA]: −1.1, 2.0), whereas open 24-HRs led to a 0.3 point (LOA: −1.2, 1.7) overestimate. Food groups most likely to be misreported using proxy data collection methods were “pulses,” “nuts and seeds,” “dairy products,” and “other fruits.” Underreporting of consumption occurred among