Related Experiment Video
Updated: Apr 30, 2026
A Precision Medicine Tool for Measurement and Monitoring of Hemoglobin S in Sickle Cell Disease Patients Receiving Transfusion Therapy
Haemoglobin concentration thresholds that discriminate functional outcomes among children aged 6-30 months in eight
Elizabeth L Prado1, Leila M Larson2, Charles D Arnold1
1Institute for Global Nutrition & Department of Nutrition, University of California Davis, Davis, California, USA.
Insights
This study suggests current anemia cut-offs for children may not align with optimal functional outcomes. New hemoglobin thresholds could better identify anemia impacting child development and activity.
Area of Science:
- Pediatric Hematology
- Child Development
- Nutritional Science
Background:
- Current World Health Organization (WHO) anemia cut-offs for children are based on healthy population hemoglobin (Hb) distributions.
- These cut-offs may not precisely reflect optimal functional outcomes in young children.
Purpose of the Study:
- To identify hemoglobin (Hb) values that best discriminate functional outcomes in children aged 6-30 months.
- To evaluate the adequacy of existing WHO anemia cut-offs.
Main Methods:
- Utilized a meta-analysis of individual participant data from studies on lipid-based nutrient supplements.
- Analyzed Hb levels and functional outcomes (physical activity, sleep, development) in children aged 6-30 months.
- Determined best discriminatory Hb thresholds using receiver operating characteristic (ROC) curve analysis.
Main Results:
- Analyzed 27,626 children across 11 datasets from 8 countries.
- Identified significant associations between Hb levels and 21 concurrent and 11 longitudinal functional outcomes.
- Found optimal Hb discriminatory thresholds varied for different outcomes, with some differing from current WHO cut-offs.
Conclusions:
- Existing WHO anemia cut-offs are in the mid-to-upper range for discriminating concurrent outcomes but lower for longitudinal development.
- This research provides evidence to inform revised Hb cut-offs for defining anemia in young children.
- Further evidence is needed to refine anemia definitions for optimal child health.
Introduction:
The WHO cut-offs to define anaemia among children (haemoglobin, Hb <105 g/L in 6-23 months and <110 g/L in 24-59 months) are based on the distribution of Hb concentrations in a healthy population. Our objective was to identify Hb values that best discriminate functional outcomes among children aged 6-30 months.
Methods:
We used previously compiled datasets from an individual participant data meta-analysis of effects of small quantity lipid-based nutrient supplements. Participants were eligible for this pooled analysis if they had Hb measured at 6-30 months and data on at least one functional outcome of interest, which included physical activity and sleep patterns, and language, socioemotional and motor development. We stratified the datasets by child age in 3-month intervals and analysed associations of Hb with both concurrent and subsequently measured (longitudinal) outcomes. If Hb significantly discriminated the 25th, 50th or 75th percentile of the outcome based on the pooled area under the receiver operating characteristic curve (AUC), we identified the Hb value with the highest concordance probability as the best discriminatory threshold.
Results:
11 datasets from 8 countries including 27 626 children were analysed. Hb significantly discriminated 21 of 47 concurrent and 11 of 32 longitudinal Hb-outcome associations. Best Hb discriminatory thresholds ranged from 102 to 111 g/L for concurrent physical activity outcomes, 103-116 g/L for concurrent developmental outcomes, and 109-117 g/L for longitudinal developmental outcomes. The I2 for the pooled AUC analysis indicated generally low to moderate heterogeneity across studies.
Conclusions:
The current WHO cut-offs to define anaemia among children are in the middle to upper range of Hb values that best discriminate concurrent physical activity and development, and are in the lower range of values that best discriminate subsequent child development. Along with other types of evidence, this study provides additional evidence to inform Hb cut-offs to define anaemia among young children.
Related Concept Videos
01:27Oxygen Transport in the Blood
01:24Factors Affecting Respiration