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Nutrition information and surveillance systems Module 10. Learning objectives. Understand the objectives of nutrition surveillance systems. Be aware of the main sources of nutrition information.
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Learning objectives • Understand the objectives of nutrition surveillance systems. • Be aware of the main sources of nutrition information. • Be aware of the variety of indicators and their appropriateness in different contexts and how different indicators relate to each other • Understand the importance of including non-anthropometric indicators in a nutrition surveillance system and how to interpret nutrition information taking into account the context, livelihood system, historical and seasonal nutrition trends. • Understand how to effectively use nutrition information to inform an appropriate response.
What kind of nutrition surveillance and information systems you know? Do you use them? For what?
Introduction Nutrition surveillance or information systems are about • collecting • analyzing • interpreting • reporting information about the nutritional status of populations and inform for appropriate response strategies.
Surveillance is a continuous process: the Triple-A cycle The Assessment stage aims to define the nutritional problem in terms of magnitude and distribution ASSESSMENT of the nutritional situation in the target population ACTION based on the analysis and available resources ANALYSIS of the causes of the problem The Analysis stage aims to analyze the causes of malnutrition as represented in various conceptual frameworks such as UNICEF
Objectives • To inform programme design and/or • To inform programme management and evaluation and/or • To inform policy-making and/or • To inform crisis management. In emergencies surveillance is also used for: • Advocacy • Identification of appropriate response strategies • Triggering a response • Targeting • Identification of cases for treatment
Which population groups should be monitored? In emergencies, acute malnutrition among children 6 to 59 months of age taken as a proxy-indicator for the general health and well-being of the entire community. Based on assumption that young children are more vulnerable than other age groups to external shocks (such as lack of food or disease) and therefore their nutritional status is more sensitive to change
Anthropometric and biochemical indicators are used to assess the nutritional status of the population • These indicators aim to answer the following questions? • Who suffers from malnutrition? (Children, elderly, mothers, etc…) • What is the type of malnutrition? (Wasting, stunting, Iodine deficiency etc…) • When? (recent or chronic problem) • Where? Which areas are most affected? • Food security, health and care practice indicators are used to analyze the causes of the nutritional problem • Why are people malnourished or at risk of malnutrition?
Anthropometric indicators • Prevalence of bilateral oedema, low WFH, low MUAC, • low HFA and low WFH, low BMI, low birth-weight Clinical and biochemical indicators • Used for micronutrient deficiencies
Underlying causes of undernutrition Potential nutritional risk factors that could be contributing to an increase in malnutrition should be identified and monitored (i.e. ‘surveyed’): • Care practices • Food security • Health • Water & Sanitation (incl. hygiene)
Underlying causes of undernutrition: care practices In emergencies, disruption to care practices can occur and have an impact on nutritional status: • Infant feeding practices • Young child feeding and complementary feeding • Food preparation and storage • Home health practices and health seeking behaviors • Hygiene practices
Underlying causes of undernutrition: food security An understanding of food access, availability and utilization at the household level is essential to understand the potential contribution of food insecurity to the nutrition situation: • Access to food • Availability of food • Utilization of food • Coping strategies
Underlying causes of undernutrition: health and morbidity To determine vulnerability and the potential contribution of health factors to the nutrition situation • Morbidity: prevalence of the main childhood illnesses (malaria, diarrhea, acute respiratory infection, measles and malnutrition) • Immunization status
Underlying causes of undernutrition: WASH Access to protected water sources and appropriate sanitation facilities is often reduced at the onset of large-scale emergencies and can be one of the main causes of diarrhea and subsequent high rates of malnutrition: • Water • Sanitation
Other indicators • In certain contexts, other indicators may be valuable for nutritional surveillance are: • Population displacement and shelter conditions • Mortality • HIV-AIDS prevalence
Key points when selecting indicators • Validity • Ease and rapidity of measurement • Reproducibility • Strength of association • Initiates a response in their own right
Methods for data collection(providing inputs in a surveillance system) • Large-scale national surveys or repeated small-scale surveys • Clinic-based monitoring • Sentinel site surveillance • School census data • Rapid nutrition assessments • Rapid screening based on MUAC measurement • Selective feeding programmes or services statistics monitoring
Large-scale national surveys • Such as Demographic and Health Surveys (DHS) or Multiple Indicators Cluster Surveys (MICS). • Good for providing baseline data and monitor long term trends • Limitations in emergencies: • Conducted every 3 to 5 years, acute malnutrition increases rapidly and could be missed • Costs
Repeated small-scale surveys • The most common method used to assess the nutrition situation in emergencies providing prevalence of all forms of malnutrition and often mortality, food security, health, WASH indicators • To be comparable they should be conducted in the same geographical area and at the same time of year/ same season • Module 7
Example of regular reporting of surveys (Nutrition Information in Crisis Situation)
Clinic-based monitoring • As component of Health Information System: in-service or community-based growth monitoring (WFA) in MCH programs. • Limitations and bias: • Capacity for identifying nutrition crisis • Captures younger children • Population attending clinics may not be representative Why?
Sentinel sites • Monitoring of a set of indicators in selected communities or service-delivery sites • Range from technically sophisticated large-scale to simple community-based monitoring of several key indicators. • Aim to produce trends in the nutrition situation in identified vulnerable areas in order to provide an early warning of deterioration • Can be inexpensive but questions around analysis of data and representativeness.
School census data • To identify high-risk populations with poor health, malnutrition and low socio-economic status • Focuses on stunting (HFA) and can provide large coverage • Limitations and bias*: • Provides information that is not useful in detecting nutritional changes during an emergency, • Attendance at school determines the representativeness of data • Its large scale does not make it easy to conduct regularly
Rapid nutrition assessments / Rapid screenings • They are an important source of information especially at the onset of an emergency to determine the magnitude and severity of a crisis. • Information may not always be representative but results can provide a basis for determining whether a more detailed assessment is required to establish the actual prevalence of acute malnutrition or whether an emergency response is required. • Module 7
Program / services statistics • Indicators such as admissions, cure, defaulting and case-fatality rates provide a measure of • programme quality • trends in acute malnutrition • the most vulnerable groups • seasonal trends in the nutrition situation, assuming reasonable coverage and access • help to identify the underlying causes of malnutrition, such as morbidity (illness) patterns.
Which is the most appropriate method for data collection in emergencies?
Frequency of data collection • It depends on the sensitivity of the indicators. • Some indicators, such as wasting, can change quickly over time in an emergency while others, such as stunting, may take many months and years to change significantly
Analysis of data • Variety of tools (software). • Quality control, major challenges: • Accurate estimation of age • Height / length measurement • Weight measurement • How to address them: • Training and ongoing supervision • Quality checks with ENA software, proposing acceptable range for main variables
Presentation of data • Compare current data with previous and establish trends: numbers in isolation mean very little. • Seasonal interpretation is also critical • Consider underlying causes and assess predictable changes in the nutrition situation: • risk factors likely to result in further deterioration • mitigating factors leading to improvement
Interpretation of data (1) • To properly understand and interpret nutritional data it should be considered: • The actual prevalence rates of acute malnutrition in relation to thresholds and decision making frameworks • Trends over time and seasonality (reviewing expected seasonal changes in nutritional status), • The underlying causes of acute malnutrition • The relationship between malnutrition and mortality • Challenge: thresholds versus trends over time and seasonality (SPHERE)
Interpretation of data (2) • Thresholds are commonly used to interpret data but rejected by many • Most of the thresholds and decision frameworks (including WHO) were decided upon NCHS references • Do they apply with new WHO 2006 child’s growth standards?
Use of thresholds WHO thresholds (based on NHCS data)
Trends over time and seasonality • How do you know whether a prevalence of malnutrition is unusual? It needs to be compared with the prevalence that is normal for the time of year for the assessed population
Trends over time and seasonality What can a sudden increase in malnutrition tell you? It can reveal something about the impact of a crisis (possibly more than prevalence at a single point in time) But it can also mean there is an outbreak of a disease, a certain food aid intervention has stopped, etc. 30-Aug-12 39
Trends over time and seasonality This means that sometimes an emergency response can be justified even if the prevalence of malnutrition has not reached the emergency threshold What can a sudden increase in malnutrition tell you? It can reveal something about the impact of a crisis (possibly more than prevalence at a single point in time) But it can also mean there is an outbreak of a disease, a certain food aid intervention has stopped, etc. 30-Aug-12 40
Malnutrition and mortality • While most guidelines recommend the collection of mortality data as part of nutrition surveys, it is not clear how mortality data can be used in nutrition surveillance. • There is a large difference between mortality data collected by surveys such as the DHS and the MICS compared to that of small-scale nutrition assessments.
WHO framework for emergency response (2) • Aggravating factors are: • Worsening of the nutritional situation • Food availability at household level less than the mean energy requirement of 2100 kcal/person/day • The GFD is insufficient (below mean energy, protein and fat requirements) • Crude mortality rate more than 1 per 10 000 per day • Epidemic of measles or whooping cough • High prevalence of respiratory or diarrheal diseases.
Dissemination of data • Timely dissemination of information is essential to put in place appropriate responses. Nutrition indicators highlight the severity of a crisis and help decision-making processes • In emergencies the nutrition situation can change very quickly. While reporting nutrition information that is older than the current season is very useful for trend analysis, the window of opportunity to address the needs effectively can be missed.
Challenges of nutrition surveillance and information systems • The biggest challenge is to ensure the link between information and action • Other issues are • reliability of data, • timeliness of reporting, • effective and efficient links to action and • sustainability
Early Warning information systems = also an example of surveillance (but broader than only nutrition) = helpful in predicting deterioration or improvement of a situation
Key messages Module 10 • Before establishing a nutrition surveillance system, be clear on the objectives and what the information will be used for. • Consider the availability of resources, staff capacity, sustainability, environmental factors and response capacity. • Review and map existing nutrition information sources (indicators collected, frequency of collection, target population) to prevent duplication and, where possible, ensure linkage or integration with existing information systems. • Define a minimum set of core indicators that refer both to nutritional status and provide an understanding of the underlying causes of malnutrition. • Design the system based on the most appropriate method. Several methods may be appropriate in some contexts. • Ensure adequate training and supervision of data collection. Include simple quality checks to assure reliability of data. • Consider contextual issues when interpreting the data: seasonality, population movement, morbidity patterns, and historical trends in nutritional status. • Ensure triangulation of information with data from other sources. • Ensure information is presented in a timely and accessible manner to decision makers and to the community. • Establish triggers to determine when more detailed nutrition assessments are necessary. • Consider how the information from the surveillance system will link to action or response. Information is meaningless unless it is used appropriately. • For longer term systems in emergency prone areas, consider sustainability issues from the outset