Prevalence of Chronic Undernutrition (HfA)
English: % of children aged 6 - 59 months with a height for age < -2 Z scores
French: % d'enfants âgés de 6 à 59 mois avec une taille pour l'âge <-2 Z-scores
Czech: % dětí ve věku 6-59 měsíců s výškově-věkovým poměrem < -2 Z-skóre
What is its purpose?
The indicator measures the prevalence of chronic undernutrition (stunting). It assesses to what degree (so called "Z-score") a child's height for age (HfA) deviates from the height of a child of the same age and sex in the 2006 WHO Growth Standards.
How to Collect and Analyse the Required Data
Children's height and age are (alongside with other data) assessed by anthropometric surveys using SMART methodology (local events calendars are used to correctly determine a child's age). SMART's website provides all the required guidance, forms, training modules as well as Emergency Nutrition Assessment (ENA) software used for data analysis and reporting.
According to WHO, the prevalence of stunting (< –2 SD) shall be interpreted as:
< 20%: low prevalence
20-29%: medium prevalence
30-39%: high prevalence
≥ 40%: very high prevalence
1) The cut-off points for moderate stunting are <-2 but >-3 SD; for severe stunting <-3 SD.
2) Reducing the prevalence of chronic undernutrition takes at least 4-5 years of a well-designed, multi-sectoral effort. Do not use this indicator for projects which are too short or do not target most of the key causes of chronic undernutrition.
3) This indicator relies on accurate age assessment. Since people often do not remember the exact dates of their children’s birth, the data collectors should never rely only on the information provided by caregivers and always verify the child’s age. This can be done by reviewing the child’s birth certificate or other documents; however, since many caregivers do not have such documents, it is essential that your data collectors are able to determine the child’s age by using local events calendars. Read FAO’s Guidelines (see below) to learn how to prepare local events calendars and how to train data collectors in their correct use.
4) Collect and report gender disaggregated data (such disaggregation is automatically produced by ENA software).
5) Always make sure that you understand and follow the local Ministry of Health's official guidance for conducting anthropometric surveys (e.g. regarding submitting a survey proposal for approval; reporting formats; use of 1977 NCHS versus 2006 WHO growth standards/ MUAC cut-off points; etc.).
6) With a larger team of enumerators (8-10 people), data collection for SMART surveys usually takes about 10 - 15 working days. Training takes 6 days (incl. piloting and standardisation test); further time is required for preparing the methodology,
Access Additional Guidance
- ACF (2014) Rapid SMART Surveys Guidelines (.pdf)
- ACF (2014) Guide: Enquêtes nutritionnelles SMART rapides (.pdf)
- PIN (2015) Practical Checklist for Conducting Nutrition Surveys (.pdf)
- SMART methodology
- WHO (2010) Interpretation Guide (.pdf)
- FAO (2008) Guidelines for Estimating the Month and Year of Birth of Young Children (.pdf)
- Nutrition Cluster Indicators Registry (incl. thresholds)