Transcript Analysis of Data for Measuring Food Availability, Access

Srinivasulu Rajendran
Centre for the Study of Regional Development (CSRD)
Jawaharlal Nehru University (JNU)
New Delhi
India
[email protected]
Objective of the session
1. To measure dietary diversity scores that a
household has consumed over the preceding
3 days or 24 hrs
1. How to calculate Dietary diversity scores
and
2.How to create other indicators of interest
from dietary diversity data
The Household Dietary Diversity Score (HDDS)
It is a simple COUNT
OF FOOD GROUPS
that a household or an
individual has
consumed over the
preceding 24 hours
(FAO Guidelines)
Food Groups?
Group No
Food Groups
1
CEREALS
2
WHITE ROOTS & TUBERS
3
VITAMIN A RICH VEG. & TUBERS
4
DARK GREEN LEAFY VEG
5
OTHER VEGETABLES
6
VITAMIN A RICH FRUITS
7
OTHER FRUITS
8
ORGAN MEAT
9
FLESH MEATS
10
EGGS
11
FISH AND SEAFOOD
12
LEGUMES, NUTS AND SEEDS
13
MILK AND MILK PRODUCTS
14
OILS AND FATS
15
SWEETS
16
SPICES, CONDIMENTS, BEVERAGES
Source: FAO
Yes = 1 No=0
Detailed commodity groups available
in
“Guidelines for Measuring Household
and Individual Dietary Diversity”
FAO
IT IS VERY IMPORTANT
TO UNDERSTAND THE
TYPE OF COMMODITY
INCULDES WHEN IT
COOKED
How HDDS reflect to Food
Security?
HDDS is meant to reflect,
in a snapshot form, the
economic ability of a
household to access a variety of
foods .
Source: FAO
Whereas, Individual Dietary
Diversity Scores aim to reflect
nutrient adequacy, BUT there
some evidences Women Dietary
Diversity Score (WDDS) also
reflects Household Economic
Access to Food
Source: FAO
Difference between
Household and Individual
Levels
Action
Household Level Questionnaire
Individual level
Questionnaire
What the
tool
measures
Household economic access to food
(dietary energy)
Quality of the individual
diet; for women
probability of
micronutrient adequacy
of the diet
Respondent Person responsible for food preparation Women aged 15-49 years
for the household on the previous day
or individuals in other
or last 3 days
age/sex groups
Target of
interest
The household (All persons living
under the same roof who share meals)
The respondent
Included
and
excluded
foods
Includes food: prepared in the home
and consumed in the home or outside
the home; or purchased or gathered
outside and consumed in the home
All foods eaten by the
individual of interest,
consumed inside or
outside the home,
irrespective of where they
were prepared
Number of
food group
included in
the score
12 groups included in the HDDS
9 groups included in the
WDDS
Source: FAO
BUT
Today we are
focusing on
“The Household Dietary
Diversity Score (HDDS)”
Data Sources
The
Household
Dietary
Diversity Score
(HDDS)
Chronic Poverty Study IFPRI
Anthropometric
indictors
Bangladesh Demographic
and Health Survey (BDHS) 2007
Reference Period
 FAO uses a reference period of the
previous 24 hrs, whereas IFPRI uses 3
days recall period.
 The recall period of 24 hrs was chosen
by FAO as it is less subject to recall
error, less cumbersome for the
respondent and also conforms to the
recall time period
When to measure dietary diversity?
 The optimal time of year to measure dietary diversity of
households or individuals depends on the objective of the
survey or monitoring activity.
 There are several scenarios to assist potential users in
planning surveys.
 More details please refer:
“Guidelines for Measuring Households
and Individual Dietary Diversity”
Source: FAO
Activities to undertake before beginning data collection
 Translation and adaption steps
(i) Basic translation
(ii) First Review
(iii) Key informant and community meeting to refine the food lists and
translations
 Technical issues to discuss prior to beginning data collection
 (i) Minimum quantities
 (ii) Individual food items that could be classified into more than one
food group (decide appropriate food group)
 (iii) mixed dishes: team will need to agree on a way to disaggregate
mixed dishes in order to record all of the individual components in
their respective food groups.
 Training Survey interviewers
Source: FAO
How to Create Dietary Diversity Scores
 As per FAO, Dietary Diversity Scores are calculated by
summing the number of food groups consumed in the
household or by the individual respondent over the 24
hrs recall period.
 Whereas, we are measuring on the basis of 3 days
recall period due to non-availability of data on 24 hrs
recall period.
Source: FAO
Step 1
 Create new food group variables for those food groups
that need to be aggregated.
 For example: HDDS the food group “Starchy staples” is
a combination of “Cereals” and “White roots and
tubers”. A new variable termed “Starchy staples”
should be created by combining the answers to
“Cereals” and White roots and tubers”.
 STATA Command:
 gen star_staple = 0
 replace star_staple = 1 if cereal ==1 | white_root == 1
 As a check, run a “Frequencies” test on all newly
created variables and make sure that all value are
either 0 or 1. There should be no values > 1 for the
newly created variable
Step 2
USING AND INTERPRETING RESULTS
 There are no established cut-off points in terms of
number of food groups to indicate adequate or
inadequate dietary diversity for the HDDS.
 Because of this, it is recommended to use the mean
score or distribution of scores for analytical purpose
and to set the programme targets.
When interpreting
the dietary
diversity score, it is
important to keep
in mind that
1. The dietary diversity score does not
indicate the quantity of food consumed
2.Diet varies across seasons and some foods
can be available in large quantities and at
low cost for short periods
3.There may be urban/rural differentials in
dietary diversity. Variety is often much
greater in urban and peri-urban centres
where food markets are adequately
supplied and easily accessible