15.5 Census sampling
You learned in Study Sessions 10 and 14 that if a survey covers the total population it is called a census. The national census takes place in most countries every five or ten years, and includes some questions about the health status of the respondents. Such a census might involve asking questions about the:
- total amount of illness in the population
- amount of illness caused by a specified disease
- nutritional status of the population
- utilisation of existing healthcare facilities and demand for new ones
- distribution in the population of particular characteristics, for example, breastfeeding or contraceptive practices.
The information obtained from a census might be used to examine the relationship between one or more of the factors investigated or the cause of a particular disease.
If you are planning a health survey in your community in which all members of the population are interviewed, this is called census sampling. It requires you to define the boundary that your study will cover (e.g. the boundary of your kebele) and then interview all the people within it. Census sampling can be used in organisations, schools and rural communities where boundaries may be easily defined.
Suppose you wanted to use census sampling to investigate the incidence of malnutrition in schoolchildren in your kebele. Who would you include in your investigation?
You would include all the children in each of the schools in your kebele.