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Definitions of Common Nutrition Terms

This document is intended to be a working definition of some frequently used nutrition terms and acronyms. It is intended to clarify meaning for

all stakeholders, including nutritionists and non-nutritionists. It is not intended to be an exhaustive list of all nutrition terms; where appropriate

reference is given for further information. It is intended to be a living document with regular reviews and up-dates.

Definition How it is measured Used to How to calculate

Prevalence (of malnutrition)

Measures the proportion of malnourished children 6-59 months in a population at a single point in time.

Estimated through

anthropometric surveys,

(true population value is

obtained only with

exhaustive survey).

Units: Percentage.

Define the proportion of children 6-59 months who are malnourished in a population at a single point in time: e.g. prevalence of GAM / MAM / SAM / Chronic malnutrition etc.

Numerator: Number of children (6-59 months) that meet the criteria for malnutrition Denominator: Total number of children aged 6-59 months surveyed

Global Acute Malnutrition (GAM)

Term used to include all children with moderate wasting, severe wasting or bilateral pitting edema, or any combination of these conditions. GAM by WHZ: - Weight-for-height z-score below -2

standard deviation units (<-2 z-scores) from the median weight of the reference population (2006 WHO Child Growth Standards) of children of the same height and/or presence of bilateral pitting oedema

Estimated through anthropometric surveys (True population value is obtained only with exhaustive survey). Expressed as a prevalence Unit: Percentage

Define the proportion of children aged 6-59 months with acute malnutrition in a population at a single point in time

Numerator: Number of children aged 6-59 months that meet the criteria for global acute malnutrition Denominator: Total number of children aged 6-59 months surveyed

Definitions of Common Nutrition Terms

May 2017

27th January 2017

9:00 - 11:00 pm

UNON Conference Room 5

27th January 2017

9:00 - 11:00 pm

UNON Conference Room 5

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GAM by MUAC: - MUAC (Mid-Upper Arm Circumference)

<125mm and/or presence of bilateral pitting oedema

Moderate Acute Malnutrition (MAM):

MAM by WHZ: - Weight-for-height z-score between minus

two and minus three standard deviation units (<-2 z-scores and ≥-3 z-scores) from the median weight of the reference population (2006 WHO Child Growth Standards) of children of the same height

MAM by MUAC: - MUAC <125mm and ≥ 115mm Moderate Maternal Malnutrition (women 15-49 years): - MUAC <230mm

Estimated through anthropometric surveys, (true population value is obtained only with exhaustive survey). Expressed as a prevalence Unit: Percentage

Define the proportion of children aged 6-59 months with moderate acute malnutrition in a population at a single point in time

Numerator: Number of children aged 6-59 months that meet the criteria for moderate acute malnutrition Denominator: Total number of children aged 6-59 months surveyed

Severe Acute Malnutrition (SAM):

SAM by WHZ: - Weight-for-height z-score below three

standard deviation units (<-3 z-scores) from the median weight of the reference population (2006 WHO Child Growth Standards) of children of the same height and/or presence of bilateral pitting oedema.

Estimated through anthropometric surveys, (true population value is obtained only with exhaustive survey). Expressed as a prevalence Unit: Percentage

Define the proportion of children aged 6-59 months with severe acute malnutrition in a population at a single point in time

Numerator: Number of children aged 6-59 months that meet the criteria for severe acute malnutrition Denominator: Total number of children aged 6-59 months surveyed

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SAM by MUAC: - MUAC <115mm and/or presence of

bilateral pitting oedema. Severe Maternal Malnutrition (women 15-49 years): - MUAC <210mm

Global, Moderate and Severe Chronic Malnutrition

Term used to include all children who are moderately or severely stunted (not growing as tall as expected for their age compared to the 2006 WHO Child Growth Standards). - Global chronic malnutrition: Height-for-

age z-score below -2 standard deviation units (<-2 z-scores) from the median height of the reference population (2006 WHO Child Growth Standards) of children of the same age.

- Moderate chronic malnutrition: Height-for-age z-score between <-2 and -3 standard deviation units (<-2 to -3 z-scores) from the median height for the reference population (2006 WHO Child Growth Standards) of children of the same age.

- Severe chronic malnutrition: Height-for-age z-score below -3 standard deviation units (<-3 z-scores) from the median height of the reference population (2006 WHO Child Growth Standards) for children of the same age.

Estimated through anthropometric surveys (true population value is obtained only with exhaustive survey). Expressed as a prevalence Unit: Percentage.

Define the proportion of children aged 6-59 months with chronic malnutrition in a given population at a single point in time

Numerator: Number of children aged 6-59 months that meet the criteria for chronic malnutrition (global and severe) Denominator: Total number of children aged 6-59 months surveyed

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95% Confidence Interval

A range in which there is a known probability of finding the true population value.

Confidence intervals are

calculated from the results

of a survey. It is

conventional to report

95% confidence intervals. .

The 95% confidence interval gives the range of possible values in which the true population value is most likely to lie (i.e. 95% of the time). If you repeat your survey 100 times with a different sample each time, the true population value would lie inside the confidence interval for 95 of these surveys. A survey estimate (i.e., the point estimate) will not be exactly the same as the true population value, even with a high level of precision and even if the sample is selected randomly and is representative and measured accurately (no bias). (The only way to determine the true population value is through an exhaustive survey. E.g., a census).

Using relevant statistical package (e.g., ENA for SMART, WHO Anthro).

Incidence1 (of malnutrition)

Occurrence of new cases of malnourished children 6-59 months in a population over a specific time period (usually one year).

Calculated by applying an

incidence correction

factor to prevalence to

estimate the total cases

Indicates the number of newly malnourished children 6-59 months in a population over a specific one year.

Incidence = Prevalence x (12/7) =

Prevalence x 1.6

See footnote2

1 Duration of SAM illness is estimated at 7.5 months. For estimating the burden of Moderate Acute Malnutrition (MAM), the same incidence rate (1.6 or higher depending on seasonality) should be applied. 2 In areas where seasonality is a concern and there are known spikes in malnutrition at certain points in the year, i.e., during the hunger season, a higher incidence correction factor (i.e. >1.6) can be applied when calculating the estimated burden for appeals, and public communication.

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occurring over the period

of a year.

Incidence = Prevalence /

average duration of

disease.

Unit: Number of children expected to be malnourished over the coming year.

Estimated burden of SAM3

The total number of SAM cases in a population over a given period of time, based on sum of current (prevalent) and new (incident) cases.

Estimated through

calculation of SAM

prevalence within the 6-

59 month population

(either nationally or within

a defined geographic area)

with incidence correction

factor

Units: Total number of

expected malnourished

children.

Indicate the number of children 6-59 months who are malnourished in a population over a given period of time.

Burden = Population 6-59mo x

(Prevalence4 + Incidence5) =

Population 6-59mo* [Prevalence +

(Prevalence x 1.6)]

Simplified: Burden = Population 6-

59mo x Prevalence x 2.6

E.g., in a child population of 1000,

a 5% prevalence of SAM would

give 50 cases. Therefore the

number of new SAM cases

expected in a year is 50 x 1.6 = 80.

Burden = prevalence + incidence =

50 + 80 = 130 children with SAM

expected in a one-year period.

3 Note that this is extremely challenging to calculate with accuracy and any calculation constitutes a very rough estimate at best. 4 NB: this is number of prevalent cases – i.e. the number of children in a given population estimated to be suffering from malnutrition at a single point in time, calculated as total number of children aged 6-59 months x prevalence (%). 5 NB: this is the number of incident cases – i.e. the number of new cases of malnutrition expected in a year.

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Target caseload

The number of children 6-59 months expected to be treated through a particular program expects within a specific time period, based on estimated prevalence and incidence, and a coverage objective.

Estimated (cannot be

measured) based on

expected incidence and

measured prevalence, or

based on previous year’s

admissions6.

Unit: Number of expected

cases to be seen in

centers over the year.

Estimate or project how many children 6-59 months the program is aiming to treat in a specific time period.

Target = Population 6-59m x

Prevalence x 2.6 x treatment

coverage (%)7

Screening (using MUAC)

Search to detect un-diagnosed cases of moderate and severe acute malnutrition in the community using MUAC and oedema. This can be carried out: - As a mass exercise in the community by:

Calling mothers/caretakers and children to a central location

Going door-to-door to look for children under 5 years.

During child health day activities During immunisation campaigns During food distributions

- As part of an initial assessment for every child under 5 years presenting to a health clinic.

MUAC tape, and pressure

test for bilateral pitting

oedema.

Unit: Number of children

(or women) found to be in

need of treatment for

acute malnutrition

Identify children aged between 6-59 months who are in immediate need of treatment for acute malnutrition, both moderate and severe, and to refer them for treatment.

Identify pregnant and lactating women in immediate need of food supplementation. The number of children found to be in need of treatment for acute malnutrition following a mass screening exercise cannot be used to estimate prevalence of acute malnutrition. This is because the rigour used for a survey to ensure most

The number of children aged 6-59 months (or women 15-49 years) that meet the criteria for GAM by MUAC should be reported (NOT the proportion). Note: Screening is a tool used for programme purposes. GAM and SAM (either by WHZ or MUAC) cannot be estimated from screening. For representative (sample or exhaustive) GAM by WHZ or MUAC data gathered on a population, see below (Rapid Assessments and Surveys).

6 This estimation implies making assumptions about the incidence of malnutrition in relation to other years. Although difficult, these assumptions need to be based in existing data. 7 If treatment coverage is known, it should be estimated based on previous year’s performance, aiming for SPHERE standards of 70% in urban areas, 50% in rural areas and 90% in camps, as well as taking into account the overall UNICEF/partner capacity to treat.

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Severe Acute Malnutrition (SAM): MUAC <115mm and/or oedema Moderate Acute Malnutrition (MAM): MUAC <125mm and ≥115mm Maternal Malnutrition (15-49yrs): MUAC <230mm

accurate possible estimates is not applied for screening exercises, the objective of which is to find children in need of treatment. Instead, a proxy-GAM and proxy-SAM can be reported if some minimum criteria for quality of screening data has been met8.

Rapid Assessment

Gathering of a limited set of key information from a specific population. Rapid Assessments can be, but are not necessarily, representative of the population. The method for a rapid assessment must always be specified and documented. For nutrition, if a Rapid Assessment includes estimation of GAM and SAM it must include individual measurements gathered from a randomly selected sample following a documented methodology.

The anthropometric measurements collected in a rapid assessment are most often MUAC and bilateral pitting oedema in order for the assessment to be fast. Weight and height can also be included. Other indicators should be kept to a bare minimum. Rapid Assessment methodologies and guidelines exist and should be followed (e.g. Rapid SMART representative survey in

Rapidly assess, with a documented degree of precision and accuracy, a changing situation or new emergency situation with regard to nutrition. If the Rapid Assessment shows a worrying situation, a full anthropometric survey should be considered.

GAM and SAM by MUAC can be calculated if Rapid Assessment is representative of the population. See above for how to calculate GAM and SAM. Prevalence estimates should be presented with confidence intervals.

8 See Guidance Note for Use of MUAC Screening Data and standard data collection templates.

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emergency contexts9, and IPC minimum guidelines – see below).

Survey10 Gathering of information through individual measurements to provide information about a specific population. For nutrition, individual children are measured to give a picture of the nutrition status of the population included in the sampling frame.

Following a set

methodology that is

clearly explained in a

survey report with

documented steps taken

to minimise bias and

ensure accuracy and

representativeness of

anthropometric

measurements.

Anthropometric measurements collected in a survey include: - Weight - Height - Bilateral pitting

oedema - MUAC - Age and sex

Anthropometric data collected in a survey is used to estimate prevalence of malnutrition (acute and chronic) after review and verification of data.

See above for how to calculate GAM and SAM. Prevalence estimates, including GAM and SAM (either/both by WHZ or MUAC) should always be presented with a 95% confidence interval to reflect the level of uncertainty around the estimate.

IPC: Integrated Food Security

- IPC is a set of protocols to classify the severity and causes of food insecurity and malnutrition and provide actionable

IPC uses existing data sets

and information, including

food security assessments,

Classify the severity of food insecurity and malnutrition into different Phases.

IPC maps showing classifications are produced following a consultative process with all

9 Rapid SMART Methodology: http://smartmethodology.org/survey-planning-tools/smart-methodology/rapid-smart-methodology/ 10 For more information on nutrition surveys refer to National Nutrition Survey Guidelines or SMART Guidelines available at http://smartmethodology.org/survey-planning-tools/

http://smartmethodology.org/survey-planning-tools/smart-methodology/rapid-smart-methodology/

http://smartmethodology.org/survey-planning-tools/

http://smartmethodology.org/survey-planning-tools/

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and Nutrition Phase Classification11

knowledge by consolidating wide-ranging evidence

- IPC is a process for building technical

consensus among key stakeholders - IPC comes with 3 different but

complementary classification scales namely IPC for Acute Food Insecurity, IPC for Acute Malnutrition, and IPC for Chronic Food Insecurity

rainfall performance,

market monitoring

information and nutrition

assessments and surveys.

IPC does not involve any

data collection.

relevant stakeholders and careful quality review of all information included.

IPC for Acute Malnutrition

- IPC for Acute Malnutrition (AMN) is a set of protocols to classify areas based on the prevalence of acute malnutrition, identify major contributing factors to acute malnutrition, and provide actionable knowledge by consolidating wide-ranging evidence on acute malnutrition and contributing factors.

Using existing information

in country on acute

malnutrition including

SMART surveys or other

nutrition surveys, MUAC

screening information

(with strict quality of data

criteria) and sentinel sites

Classify the severity of acute malnutrition:

IPC Phase

Description

GAM by MUAC

GAM by WHZ

IPC 1 Normal <6% <5

IPC 2 Alert 6-10.9% 5-9.9

IPC 3 Serious 10-14.9

IPC 4 Critical 11-16.9%

15-29.9

IPC 5 Extreme Critical

>17% >30

IPC maps showing classifications are produced following a consultative process with all relevant stakeholders and careful quality review of all information included.

11 IPC Website: http://www.ipcinfo.org/

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This is a living document and will be up-dated on a regular basis.

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ANNEX 1: GUIDANCE NOTE FOR MUAC SCREENING

DEFINITION OF SCREENING: Search to detect un-diagnosed cases of moderate and severe acute malnutrition in the community using MUAC (and oedema).

OBJECTIVE OF SCREENING: To identify undetected cases of acute malnutrition in the community and refer for treatment in order to improve program coverage.

LIMITATIONS OF SCREENING FOR PREVALENCE ESTIMATION: MUAC screening does not follow any particular methodology. It can be carried out:

o As part of child health days o As part of routine services at health facility level o House-to-house as a community-based mass MUAC screening exercise often targeted to hot-

spot areas or difficult to access areas o Mobilizing mothers / caretakers to bring their children to a central location for screening o Exhaustive screening of all refugees at arrival points

There is no sampling methodology (to minimize bias) followed

There is very limited training for MUAC measurement and no standardization testing of measurers

There is often very limited to no supervision

Even when very many children are screened these limitations still apply. Screening a very large number of children does not improve the quality of the data.

USING DATA FROM MUAC SCREENING:

MUAC screening is a valid program intervention to improve coverage and should continue as needed.

Data cannot be used for estimation of prevalence or for calculating caseload UNLESS:

Screening data has been disaggregated by age (children above / below 2yrs) and sex at collection. This is in order to control for the known age and sex bias of MUAC.

Some information about the way the screening was carried out is provided:

o Some general information on the location and type of population screened (e.g. IDPs / Refugees / residents etc).

o A brief description of the method used for the screening (house to house exhaustive / house to house with a skip pattern / screening at a fixed post, e.g. clinic or OTP / random or EPI sampling).

CHECKLIST: Quality Criteria required 1. Age (above/below 2yrs) and sex disaggregation of

results. 2. Exhaustive screening, simple or systematic random

sampling has been used and documented in the methodology.

3. Community based screening (not facility based). 4. Details of total population in area screened and

purpose of screening are provided. 5. Use of standard templates for collection of

screening data (Excel file) and calculation of results.

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o A brief description of the purpose of the screening (e.g. screening on arrival of IDPs or Refugees / as a part of child health days or immunization campaigns / dedicated acute malnutrition case-finding etc).

o The estimated total population in the area screened is provided.

REPORTING:

The standard template for collection of MAUC screening data (Excel file) should be shared for validation.

The number and percent of oedema cases should be reported.

The number of children referred for treatment (disaggregated by MAM and SAM) should be reported.

The number of children admitted into treatment following referral must be followed up and reported. This information should be gathered from treatment programs and added to the MUIAC screening report when available.

COMMUNICATION OF RESULTS:

Results from a MUAC screening exercise should never be referred to as a ‘GAM’ and/or ‘SAM’. GAM and SAM are estimates of prevalence that can only be calculated from a Survey or Rapid Assessment that meets agreed quality criteria (e.g. as in ENA for SMART).

If the screening does meet the quality criteria described above:

Results can be communicated as a proxy GAM and proxy SAM.

If the screening does not meet the quality criteria described above:

Results of screening should be reported as the number of children found in urgent need of treatment for severe acute malnutrition / the number of children found in need of treatment for moderate acute malnutrition.

A proportion should never be calculated from the results.

KEY MESSAGES MUAC screening is a valid program intervention to increase coverage of selective feeding

programs and should continue as needed.

MUAC screening data can only be used for program targeting, proxy GAM / proxy SAM

estimation and/or caseload estimation if the above quality criteria have been met.

If the results, meeting the criteria above, are alarming then a survey (e.g. SMART) should be considered.

If none exist, interventions should always be started to treat the children identified with acute malnutrition through screening. Survey results should not be awaited before treating children in need.

All children identified with acute malnutrition through screening should be referred for treatment (either for moderate or severe acute malnutrition), and followed up to ensure they are admitted.

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