Overview
Nutritional indicators are used to screen, diagnose, and evaluate interventions in
individuals. They are also used in populations to determine the gravity of nutritional
problems, their location and causes, and to evaluate the impact of programs and
policies.
This module is broken down into the following sub modules:
 Biochemical
 Anthropometric
 Clinical
 Dietary
Anthropometric
The purpose of anthropometric assessment is to take measurements and relate those
data to standards or reference data. There are a number of anthropometric
measurements that can be taken but the main ones related to population assessment
are weight and height or length.
In addition to the tools that can be found in this toolkit detailed procedures for various
anthropometric measurements can be found in the MGRS anthropometric training video
and in the module, Measuring a Child's Growth, of the WHO child growth assessment
course, available at www.who.int/childgrowth/training. Anthro Software for analyzing
anthropometric data is available on the WHO website at
http://www.who.int/childgrowth/software/anthro_pc_manual.pdf.
Clinical Signs and Symptoms
Micronutrient deficiencies are often hidden problems in the population, with only the
most severe forms showing symptoms. Ideally micronutrient deficiencies should be
assessed biochemically but in some circumstances this is not always feasible. One
alternate method is the assessment of the clinical signs and symptoms produced by
various specific deficiencies. Although clinical signs and symptoms often appear only in
the most severe cases, resulting in a gross underestimate of the prevalence of
deficiency, they can indicate whether or not a specific deficiency is a severe problem in a
population.
Assessment of clinical signs and symptoms is often inaccurate because it depends on
the expertise of the survey workers carrying out the examination. Because many
deficiencies are relatively rare, few health workers have substantial experience with
recognizing their signs and physical manifestations and there is high inter-observer
variability is high. In addition, many of the signs and symptoms produced by
micronutrient deficiency may have many other causes unrelated to nutrition.
In general an assessment of clinical signs in national surveys is not common but may
still be a part of an assessment in refugee or displaced populations.
In this module there is a presentation with pictures and descriptions of clinical signs and
a list of useful references for those people wishing to incorporate a clinical assessment
into their survey.
Biochemical
Biochemical indicators are critical in the assessment of micronutrient status. Because
such indicators may change more rapidly after the implementation of a treatment or
preventive intervention, their measurement may demonstrate effectiveness sooner than
other indicators, such as anthropometry or clinical signs and symptoms. However,
collection of the specimens necessary to test biochemical indicators is substantially
more complex than interviewing household respondents or weighing and measuring
children or adults.
This module contains tools and references specially related to biochemical indicators
and cut offs. Information on processing, shipping, labeling and storage can be found in
the laboratory module.
Dietary
For large cross sectional surveys, food frequency or 24-hour food recall modules to
assess micronutrient status are rarely included, but may include a modified food
frequency questionnaire. If a country has a specific intervention to increase the intake of
a particular micronutrient, there are certain questions that can be included in the survey
to assess exposure to factors that enhance or inhibit intake and absorption. For example
a country might have various programs to improve iron status in the population and they
might want to assess factors that can affect iron absorption, such as tea and coffee
consumption.
If countries have fortification programs, questions related to the use of the fortified
products are usually included in the data collection forms. For some surveys it is
necessary to obtain a small sample of the food for laboratory testing.
For countries that want to conduct a dietary assessment there are tools that can help to
estimate intakes of vitamin A and iron and zinc. There are also guidelines for the
collection of salt and bread for laboratory testing. In the Resources section there are
various guidelines and manuals and references on dietary indicators.