Development and validation of a dietary iron score for screening populations at risk for inadequate iron intak

Abstract

© 2018, Malaysian Journal of Nutrition. Introduction: Inadequate iron intake is a determinant of iron deficiency. A simplified tool for dietary assessment is needed. This study aimed to develop a dietary iron scoring system (DISS) and to determine the validity of the dietary iron score (DIS) for screening populations at risk for inadequate iron intake. Methods: A three-step process was undertaken to develop the DISS, namely (1) iron score (IS) for each food was constructed based on its iron content per 100 g, adjusted for heme content equivalence; (2) the predicted modifying effect (PME) was formulated based on either enhancing or inhibiting effects of dietary constituents; (3) the DIS of a meal was obtained by multiplying the total IS and the PME of that meal. The validity of the DIS for screening populations at risk for inadequate iron intake was determined against absorbable iron calculated by the Hallberg & Hulthen algorithm. A probability of adequacy of absorbable iron intake of 0.75 was used as a cutoff in defining the population at risk. Results: There was a significant correlation between the absorbable iron and DIS (r=0.34, p < 0.001). Using the Receiver Operating Characteristic (ROC) curve, three cutoffs of DIS, namely 5, 6 and 7, had comparable results. However, sensitivity (82.9%) and specificity (50.0%) was the best for DIS cutoff of 7. Conclusion: The proposed DISS is potentially a field-friendly tool for screening populations at risk for inadequate iron intake. Further verifications are needed, using more complete dietary data.