Beyond Conventional Anthropometric Indicators: A Systematic Review of Composite Measures for Assessing Undernutrition Among Under Five Children

<title>Abstract</title> <p>Background Conventional anthropometric indicators of child undernutrition — stunting, wasting, and underweight — are typically reported separately and do not capture children experiencing more than one form of failure at once, which may cause the overall burden of undernutrition to be underestimated. The Composite Index of Anthropometric Failure (CIAF) integrates these dimensions into a single classification. This review synthesized the methodological characteristics, classification schemes, data quality, and comparative performance of CIAF and its variants. Methods PubMed, Scopus, Web of Science, CINAHL, and ProQuest were searched for peer-reviewed, English-language studies published from January 2016 onward that applied a composite anthropometric measure to children under five years of age. Screening followed PRISMA 2020 guidance, and study quality was appraised using Joanna Briggs Institute checklists. Findings were synthesized narratively. Results Of 1,111 records identified, 21 original studies from 10 countries met inclusion criteria. Five composite measures were identified, with the original CIAF used most frequently. Every included study found that CIAF identified a higher prevalence of undernutrition than any single conventional index, with discrepancies ranging from 10.2 to 35 percentage points. Between 13.3% and 49.2% of children had multiple concurrent failures. Methodological reporting was often incomplete: 33% of studies did not report the software used for z-score calculation, 48% did not report survey weighting, and 86% did not report flagging of biologically implausible values. Where tested, children with multiple failures had substantially higher odds of morbidity than children with no failures. Conclusions CIAF appears to provide a more comprehensive assessment of childhood undernutrition than conventional single indicators and may warrant consideration as a complementary surveillance measure. Substantial methodological heterogeneity across studies, however, limits comparability, underscoring the need for standardized reporting guidelines for composite anthropometric measures.</p>