Multiple Indicator Surveillance 1997

The NMIS uses a methodology known as Sentinel Community Surveillance (SCS). It has the underlying aim of 'building the community voice into planning'. SCS can be described as a multi-sectoral community-based information management system. There are a number of particular features of the SCS methodology:

• Data are collected from cluster sites, selected to be representative of a district, a region or a country.
• Typically, cluster sites are communities of around 120 households, and all households in the site are included in data collection.
• SCS is a repeated cyclical process, with each cycle including planning and instrument design, data collection, data analysis and interpretation, and communication of results.
• Each cycle focuses on a particular area or problem, rather than trying to collect data on a wide range of problems.
• Quantitative data from household questionnaires are combined with qualitative data from focus groups, key informant interviews and institutional reviews from the same communities (that is, the data are coterminous) to allow a better understanding of the quantitative data. This combined analysis is called mesoanalysis11.
• Data analysis is not only in terms of indicators (for example, rate of childhood diarrhoea) but also in terms of risk (for example the risk of diarrhoea in a child with access to safe water compared with a child who does not have access to safe water).
• Data analysis, and especially risk analysis, is intended to produce results in a form that can be useful for planning at household, community, district and national levels.
• The same sites are revisited in subsequent cycles of data collection, allowing easy estimation of changes over time or as a result of intervention.
• Each cycle of data collection and analysis requires a communication strategy to get the information to those who need it for planning.

Transfer of skills of data collection, analysis and communication over a number of cycles is an explicit aim of the methodology.

A key feature of SCS is the ability to do risk analysis to look at causes. In NMIS cycle five focuses on care for women during pregnancy and delivery and the relationship between this and the outcome of pregnancy, in terms of estimates of low birth weight and survival of the baby SCS is deliberately designed to concentrate data collection efforts: in time (a series of cycles in the sentinel sites, at approximately 6 monthly intervals); in space (representative communities are surveyed rather than collecting data from all communities); and in subject matter (each cycle focuses on one area at a time, rather than trying to collect all possible data on every occasion). SCS employs a type of cluster survey methodology, but the clusters are larger than in many cluster surveys: typically 100-120 households per site, rather than the 10-50 used in most cluster surveys.
And in the SCS method, there is no sampling within each site; every household is included. This gives greater statistical power in the data analysis and also allows the linkage of data from the household questionnaires to other, mainly qualitative, data from the same sites. This data relating to the whole site is combined with the household data in a mesoanalysis11.

A key issue in the SCS methodology and in the NMIS is the selection of sites so as to be representative. In some countries, random sampling is not a possibility because no adequate sampling frame exists. In these situations, purposive selection is used, drawing on local knowledge of conditions to choose sites as representative as possible of the situation in a district, region or country. When possible, random sampling methods are used and this is the case in Nepal, where a reasonably good census sampling frame exists. In both cases, stratification is first used to ensure that certain types of sites are included in proportion to their occurrence in the population. For example, stratification can be by urban and rural sites, or by ecological zones. In the NMIS, the sample sites for the NMIS were drawn by the Central Bureau of Statistics (CBS), after stratification into development regions, ecological zones and urban/rural sites. The details of the sampling method and the selected sites are given in the report of the first NMIS cycle and the annexes to that report.

The sites in NMIS cycle 5 are selected by a multistage random sampling method. The sites are representative of the country, of the five development regions, of the three ecological zones, of the 15 eco-development regions, and of urban and rural situations. The rural sites were selected primarily to give representation of the 15 eco-development regions but in 18 districts there are sufficient sites (four or more) to ensure reasonable district representativeness. In a further 19 districts, only 1-2 sites were selected so they cannot be relied upon to be representative of that district. Note that representation of the 15 eco-development regions is among the rural sites only; the urban sites are stratified separately and are not intended to be part of the representation of the different eco-development regions. This reflects the high proportion of the population living in rural communities (around 90%) and the difficulty of having a large enough urban samples to stratify separately among the 15 eco-development regions.

There are a total of 144 sites in the sample: 126 rural and 18 urban. A total of 18,996 households and 106,160 household members were interviewed in the survey.