what is it ?

A Link NCA is a structured, participatory, holistic study, based on the UNICEF causal framework, intended to build evidence-based consensus

The Link NCA is a mixed method combining a strong and expert level qualitative component with a descriptive quantitative component to answer the following research questions:
  1. What is the prevalence and severity of wasting and/or stunting in the study population ?
  2. What is the prevalence of key risk factors for under-nutrition among the population ?
  3. What are the causal “pathways of under-nutrition” ?
  4. How have the prevalence and causes of stunting and/or wasting in this population changed over time?
  5. Which causal pathways are likely to explain most cases of under-nutrition?
  6. What recommendations can be made for improving nutrition security programming?
The Link NCA studies the local population, typically at a district or livelihood zone level.

Download the booklet that gives an overview of the methodology
© ACF Sandra Calligaro
The measurement of the mid-upper arm circumference (MUAC) is an indicator used in the diagnosis of acute malnutrition

UNICEF causal framework

Linking stakeholders accross different sectors

The Link NCA  gathers local communities, technical experts, scientists, political leaders from different fields of expertise (Nutrition and health, care practices, mental health, sanitation, food security and livelihood, education, social sciences...).

Stakeholders meet during an initial workshop to identify causal hypotheses. They also meet during a final workshop (after data collection and analysis is completed by the NCA Analyst) to reach a consensus about the plausible causes of under-nutrition.

This process is essential to having a holistic approach and initiating a coordinated local response.

Linking analysis to a programmatic response

The Link NCA is designed to improve Nutrition Security Programming by providing operational recommendations for Nutrition Specific and Nutrition Sensitive interventions.

Linking risk factors and under-nutrition to identify pathways

The Link NCA is based on the UNICEF conceptual framework on the causes for under-nutrition which seeks to understand the local pathways of under-nutrition.

Although the UNICEF framework is substantial, it it proves essential to 1) identifying local blockages which is crucial to identifying specific solutions and 2) to identifying linkages accross different sectors.
© ACF Agnès Varraine-Leca
Survey questionnaire

How does the analyst gathers opinions of vulnerable groups in the Link NCA method?

« Initially through the qualitative survey. Focus groups include participants who often belong to vulnerable groups: mothers, malnourished children ...
They have the opportunity to explain how they perceive the causes of malnutrition, what they would like to change and how they would. This allows us to highlight their needs, the reasons they perceive but also their priorities. »

G. Luc, NCA Analyst in DRC (2014)

The main steps of a Link NCA

What the Link NCA method is not

The Link NCA is not a “quick and dirty” or “rapid” method: the Link NCA process requires approximately four to five months to complete. Planning for the method must take realistic account of the time required.

The qualitative portions of the Link NCA are designed to provide an in-depth picture of the nutrition situation in a relatively small geographic area. It is not always possible to generalize the results of this enquiry to other parts of the country.

The Link NCA is not an emergency assessment tool: it is not well suited for application in rapid onset crises due to the time required to conduct the study. Furthermore, in acute emergencies the immediate causes of under-nutrition will likely be overt and prioritised over underlying and basic causes. The Link NCA can provide an excellent baseline (pre-emergency point of com- parison) that can aid in interpreting the extent and significance of deterioration that has occurred after an acute shock.

The Link NCA method does not seek to statistically demonstrate nutrition causality but instead creates consensus around the plausible causes of under-nutrition in a localized context. Initially, the Link NCA was designed to rely primarily on statistical tests of causality to inform conclusions; after testing, this approach was rejected by the scientific committee for the following reasons:

  - The ideal study design for determining causality at the level of known probability is rarely achievable in field settings: a single cross-sectional survey cannot indicate causality. A case-control design is not always appropriate for understanding risk factors of low height- for-age and weight-for-height along a spectrum of severity. Most operational contexts cannot afford to implement a longitudinal panel study. Evaluations can provide evidence of causality when observed changes in risk factors are attributed to an intervention, however most NCAs will be performed prior to designing a program.

  - Limited variability in certain risk factors, such as education levels, means that bivariate and multivariate analysis have inadequate power to detect associations with under- nutrition unless an unfeasibly large sample is included in the study

  - Certain important risk factors are difficult for field practitioners to measure quantitatively (e.g., maternal depression, low birth weights).

  - Some risk factors might play a minor role at the time of the survey but may be important the next season (e.g., malaria; diet diversity) or may have been important to child growth a couple years prior to the survey.

  - In order to quantitatively analyse the relationships implied by the global UNICEF causal framework, a statistically complex “path analysis” is appropriate, but too advanced, for most field practitioners.

  - Results can even be misleading: experience suggests that stakeholders tend to over-focus on statistical results, even if limitations are stated, and under-appreciate other sources of information that can provide a more holistic picture of the local situation.