Transcript Document

Measuring
malnutrition at
individual level
Module 6
18-Jul-15
1
Learning objectives
• Be familiar with the standard methods used to
measure weight, height, mid-upper arm circumference
(MUAC) and oedema.
• Understand the classifications of undernutrition in
children and adults using different anthropometric
indices.
• Be able to identify Z-score ranges for weight-for-height
for children 6-59 months using the 2006 WHO Growth
Standards simplified field tables for boys and girls
• Be aware of the uses of anthropometric measurements
in both emergency and non-emergency contexts.
• Be aware of the limitations of anthropometry.
18-Jul-15
2
18-Jul-15
3
Measurements for undernutrition
•
•
•
•
Anthropometry or body measurements
Clinical assessment
Dietary intake
Biochemical assessment
18-Jul-15
4
•
•
Body measurements and clinical assessment
for acute malnutrition
Age and sex
Anthropometry




Weight
Height (or length)
Middle-upper Arm Circumference (MUAC)
Clinical signs



Presence of bilateral pitting oedema
Presence of medical complications
Absence of appetite
18-Jul-15
5
18-Jul-15
6
18-Jul-15
7
18-Jul-15
8
18-Jul-15
9
18-Jul-15
10
Use of MUAC for children 6-59 months
• MUAC (Mid upper arm circumference) is measured in
the middle of the left arm of children and is a proxy for
measures of reserves of fat and muscle in the body.
It is an effective predictor of death in children 6 to
59 months, but it tends to select more younger
children
18-Jul-15
11
18-Jul-15
12
Clinical assessment and acute
malnutrition


Presence of bilateral pitting oedema:
Assessment for medical complications and
appetite
18-Jul-15
13
Checking for oedema
18-Jul-15
14
Anthropometrical or nutritional indices
• Combination of two measurements:
– Weight and age : WFA
– Height (or length) and age : HFA
– Weight and height (or length): WFH (or
BMI)
18-Jul-15
15
Use of anthropometrical indices at
individual level
• To determine the condition of an individual by
comparing to expected anthropometric values for an
individual of the same sex and age, e.g. a growth
standard or growth reference. Then:
– Classify the nutritional status of individuals, e.g. whether
they present or not malnutrition, according to specific cutoff points, and
– Decide whether the individual needs to be treated or not
• Some indices don’t need to be compared with
references, thresholds are used instead (BMI).
18-Jul-15
16
Which standards / references do we use?
• For children, for each height standards of
weight are expected:
• The 2006 WHO Growth Standards are universal
standards of growth for children and also provide
a classification for malnutrition: <-3 SD for severe
malnutrition, <-2 SD for moderate malnutrition
• WHO and UNICEF also endorsed the use of
MUAC <115 mm as a criteria for severe
malnutrition for children 6 to 59 months.
18-Jul-15
17
Normal distribution of weight for an specified
height (Growth standards)
Median weight for 80
cm tall boys
Standard deviation = 1.05
18-Jul-15
18
Anthropometry and acute
malnutrition

Wasting:




low weight-for-height (WFH) or
and/or low mid upper arm circumference
(MUAC) or
low BMI (for adults)
MUAC and BMI are interpreted directly with
cut-off points, without comparison to a
reference (index)
18-Jul-15
19
Acute malnutrition in children 6-59 months
• The basic information and body
measurements needed to assess acute
malnutrition in children 6-59 months are:
– Age and sex,
– Anthropometrical measurements: weight,
height/length and MUAC,
– Clinical signs of visible wasting, bilateral edema,
medical complications and lack of appetite
• The nutritional index is WFH
18-Jul-15
20
For children aged 6-59 months
Classification of acute malnutrition
WFH (wasting)
MUAC
Bilateral Oedema
Moderate acute
malnutrition
(MAM)
Severe acute
malnutrition
(SAM)
≥ -3 SD & < -2 SD
< -3 SD
≥ 115mm & < 125mm
< 115mm
No
Yes
18-Jul-15
21
Classification of acute malnutrition
Acute malnutrition
Moderate acute
malnutrition
Weight for height ≥-3
ZS
and <-2 ZS
Or
MUAC ≥11.5 and
<12.5 cm
Severe acute
malnutrition
Without medical
complications
Weight for height <-3 ZS
Or
MUAC <11.5 cm
Or
Bilateral pitting edema
and no medical complications
Severe acute
malnutrition
With medical
complications
Weight for height <-3 ZS
Or
MUAC <11.5 cm
Or
Bilateral pitting edema
and medical complications
18-Jul-15
22
For infants less than 6 months
• Criteria for malnutrition are based on clinical signs
(e.g. oedema, visible wasting, too weak to suckle,
not gaining weight despite feeding) and risk
factors (e.g. insufficient breast milk, absence of
mother
• Birth weight (< 2,500gr) is a recognized measure,
but does not account as malnutrition criteria. LBW
is used as indicator of issues during pregnancy
(like IUGR) and represents a risk factor for
subsequent malnutrition
18-Jul-15
23
For older children and adolescents
(5-19 years of age)
BMI-for-age Z-score
Severe thinness:
Thinness:
<-3SD
≥ -3 SD & < -2 SD
BMI-for-age calculations are based on the use
of the WHO growth references
18-Jul-15
24
For adults (20 – 59.9 years)
BMI
(WHO
1995)
Wellnourished
Mild acute
malnutrition
Moderate acute
malnutrition
Severe acute
malnutrition
≥ 18.5kg/m2
<18 to
≥17kg/m2
<17 to
≥16kg/m2
< 16kg/m2
• For pregnant and lactating women MUAC is
recommended:
– MUAC <210 mm indicates a nutritional risk requiring
intervention. Normality is defined at >230 mm.
18-Jul-15
25
For elderly (over 60 years old)
– Very difficult to measure: age for being
considered old differs between settings or
possibility to take accurate measures is
limited.
– Same cut-offs as BMI for adults should be
used for identifying older people suffering
from malnutrition.
18-Jul-15
26
Anthropometry and chronic
malnutrition
• Stunting is indicated by low height-forage (HFA)
• Underweight is indicated by low
weight-for-age (WFA)
18-Jul-15
27
Stunting and underweight in children
6-60 months
• The three nutritional indices of WFH, HFA, and WFA
each assess different aspects of growth failure.
• Tables exist in the WHO growth reference for
measure of each of them:
HFA (stunting)
WFA (underweight)
Moderate stunting
Severe stunting
<-2 SD to ≥-3 SD
< -3 SD
Moderate underweight
Severe underweight
<-2 SD to ≥-3 SD
< -3 SD
18-Jul-15
28
Growth Monitoring charts (WFA index)
18-Jul-15
29
Measuring the different forms of undernutrition


Acute
malnutrition


Chronic
undernutrition
(stunting)



Underweight
(acute and/or
chronic)


Micronutrients
deficiencies

Acute malnutrition is indicated by wasting and/or bilateral oedema.
Wasting is measured by the nutritional index of WFH or mid upper arm
circumference (MUAC).
Bilateral oedema, found in cases of kwashiorkor and marasmickwashiorkor, is an abnormal infiltration and excess accumulation of
serous fluid in connective tissue or in a serous cavity.
Other clinical signs are presence of medical complications and anorexia
Stunted children are short for their age (low height-for-age (HFA).
Stunting is measured by the nutritional index of HFA.
Underweight children weigh less than the average weight for children of
the same age and sex.
Underweight is measured by the nutritional index of weight-for-age
(WFA)
Direct assessment: measurement of actual clinical or sub-clinical
deficiency in individuals
Indirect assessment: estimation of nutrient intakes at a population level
and from this the risk of deficiency and the likely prevalence
18-Jul-15
30
Key messages Module 6
•
•
•
•
•
•
Anthropometry is the use of body measurements to assess and classify nutritional status in an
individual.
Other measurements include clinical, biochemical and dietary intake assessment
Body measurements include: age, sex, weight, height / length and mid-upper arm circumference
Clinical signs of acute malnutrition include: visible wasting, bilateral oedema and lack of appetite
Acute malnutrition among children 6-60 months is assessed using the nutritional indices of
weight-for-height or weight-for-length (WFH), MUAC, and signs of bilateral oedema.
Acute malnutrition for other age-groups:
–
–
–
–
•
•
Infants less than 6 months of age is assessed using visible signs of wasting and bilateral oedema. Social criteria such as an absent mother or
inadequacy of breastfeeding can indicate nutritional risk.
Undernutrition among children and adolescents 5-19 years is assessed using the nutritional index of body mass index for age (BMI-for-age)
and clinical signs.
Adult undernutrition is assessed through Body Mass Index (BMI) (either adjusted or unadjusted by Cormic index) or MUAC in addition to
clinical signs. MUAC is the preferred nutritional index during pregnancy and up to 6 months postpartum.
There are numerous issues related to the assessment of undernutrition in the elderly, however BMI is recommended in addition to clinical
signs.
The use of the 2006 WHO Growth Standards is now recommended over the use of the 1978
National Center for Health Statistics growth reference (NCHS GR) in the definition of acute
malnutrition in children 6-60 months. The 2007 WHO Growth References is recommended for use
in assessment of children and adolescents 5-19 years.
Nutrition indices should be presented as Z-scores as opposed to percentage of the median.
Percentage of the median is no longer recommended for use in classification of individual
nutrition status.
18-Jul-15
31