4. Monitoring, surveillance and evaluation
The implementation of food-based strategies to prevent micronutrient deficiencies may involve a complex series of activities which cannot be entirely planned in advance. There will always be a need to take complementary and corrective measures as implementation proceeds. Ongoing programme monitoring can help to ensure that implementation proceeds smoothly and that problems are dealt with as they arise. Monitoring implies continuous gathering, analysis and review of information to redesign and strengthen the programme. Monitoring helps to ensure accountability, which in turn furthers sustainability. It also provides feedback that can be used for inservice training of programme staff.
Programme monitoring must be simple and inexpensive to carry out. Otherwise, it may be discontinued. Wherever possible, communities that are the targets of food-based programmes should be involved in programme monitoring. Monitoring of gardening programmes is discussed in Section 2.1.3; monitoring of food fortification programmes in Section 2.5.8; and monitoring of communication programmes in Section 2.6.7.
In some situations it is useful to maintain continuous surveillance of the micronutrient status of a population. Although this can sometimes be done through repeated surveys, intermittent reporting from small numbers of sentinel sites will generally be more efficient.
Figure
The objective of food-based strategies to promote the consumption of micronutrient-rich foods is the availability of an abundance and variety of healthful foods, as in this Malaysian market.
Surveillance indicators should be culturally acceptable, feasible to obtain under field conditions and reasonable in cost and should have adequate sensitivity and specificity. The choice of indicators will be influenced by local needs and the institutional capacity of the country concerned. For many countries, developing the capacity to perform complex laboratory analyses requires long-term investment in manpower training, capital investment in laboratory equipment and a commitment of recurrent funds, often in foreign currency. UN agencies are continuing to work on the development of appropriate surveillance indicators for micronutrient programmes.
The World Health Organization (WHO) and UNICEF (1994a) have developed a preliminary set of indicators for vitamin A deficiency (VAD). These draft indicators propose cut-off points for various levels of severity related to biology (clinical or eye signs), function (night blindness), biochemistry, histology and illness. These indicators can also be used to conduct assessments and evaluation surveys. In addition, diet-related indicators were designed to identify populations at risk of VAD:
n more than 50% of infants aged less than 6 months are not being breastfed;
n fewer than 75% of children 6-18 months of age receive vitamin A-rich foods 3 times a week;
n dark green leafy vegetables are unavailable in local markets for 6 or more months of the year;
n fewer than 75% of households consume vitamin A-rich foods 3 times a week; and
n fewer than 75% of children aged between 6 months and 6 years and fewer than 75% of pregnant and lactating women consume vitamin Arich foods at least 3 times a week.
WHO, UNICEF and the International Council for the Control of iodine Deficiency Disorders (ICCIDD) have also proposed prevalence indicators for the assessment of iodine deficiency disorders. (See Table 4.1.) Similar prevalence indicators are being developed for iron deficiency anaemia by WHO.
Target Population |
Severity of Public Health Problem Prevalence | |||
Indicator |
Mild |
Moderate |
Severe | |
Goitre grade > 0 |
SACa |
5.0-19.9% |
20.0-29.9% |
³30.0% |
Thyroid volume > 97th centile by ultrasoundb |
SAC |
5.0-19.9% |
20.0-29.9% |
³30.0% |
Median urinary iodine level (µg/L) |
SAC |
50-99 |
20-49 |
<20 |
TSH > 5mU/L whole blood |
Neonates |
3.0-19.9% |
20.0-39.9% |
³40.0% |
Median Tg (ng/mL serum)c |
C/Ad |
10.0-19.9 |
20.0-39.9 |
³40.0 |
Source: WHO/UNICEF/ICCIDD (1994).
a SAC = school-age children.
b Normative thyroid volume size values (WHO and ICCIDD 1995).
c Different assays may have different normal ranges.
d C/A = children and adults.
The purpose of programme evaluation is to determine the extent to which goals and objectives have been achieved. Studies which focus on the output of programme components are sometimes termed process evaluation, while studies of programmes' effects on micronutrient status are termed impact evaluation. Intermediate-level indicators, which measure improvements in the production and consumption of micronutrient-rich foods, are more appropriate for programmes which focus on diet alone and do not include public health or other interventions which address other causes of micronutrient deficiency.
Gillespie and Mason (1994) reviewed the results of outcome evaluations of vitamin A programmes (including two breastfeeding interventions, 13 dietary modification programmes and four fortification programmes). Breastfeeding was found, retrospectively, to be associated with a reduced risk of xerophthalmia. Fortification programmes were found to be effective at raising serum retinol levels in children and adults within 1 year of initiation. Evaluation of a study in Bangladesh found, retrospectively, that children living in households with home gardens were less likely to suffer from xerophthalmia.
Outcome evaluations of seven home gardening interventions and four interventions that included social marketing factors were also reviewed. Comparison of these programmes was difficult because they used enormously varying designs and evaluation methodologies. However, all evaluations showed indirect benefits, including increases in female income. Most showed an increase in production of vitamin A-rich foods. Where programmes included an educational component, the evaluations found that the target population's knowledge of the importance of vitamin A-rich foods increased. Some evaluations showed increases in consumption of vitamin A-rich foods, but few were able to show impact on vitamin A status. Costs were found to be low. A programme to decrease night blindness in northeastern Thailand cost US$0.42 per capita target group per year. In West Sumatra, Indonesia, the cost of increasing consumption of dark green leafy vegetables to sufficient levels was US$0.28 per mother/child unit. A large programme in Bangladesh covering a population of 1.9 million had a measurable positive impact on the diet of young children within only 3 years. The annual cost to increase both production and consumption of carotene-rich foods was US$0.11 per person (Greiner 1993).
Government and donor support for food-based strategies has been lacking in part because of insufficient monitoring and evaluation and inadequate communication of the successful results of many dietary diversification, food fortification and communication programmes to overcome micronutrient malnutrition. A comparison of the cost-effectiveness of food-based programmes versus supplementation has demonstrated that the former are preferable because they are generally less costly, more sustainable, better able to target vulnerable groups and have multiple nutritional benefits (Greiner 1993). The inclusion of solid monitoring and evaluation components in all food-based programmes would not only improve implementation but also contribute to demonstrating the comparative effectiveness of food-based approaches to preventing micronutrient deficiencies.
