Introduction to standardisation (cont.)
What is standardisation?
These plots show, for each country, the number of people (on the x-axis, with men on the left, and women on the right) subdivided by age group.
Suppose we need to compare mortality rates in two different countries, Sweden and Ecuador. In 1994 the crude death rate in Sweden was 10.5 per 1000 person-years, and in Ecuador was 5.6 per 1000 person-years. Does this mean that the risk of dying in Sweden was greater than in Ecuador?
The problem with this comparison is that the two populations under study have very different age structures. This is illustrated by the diagram.
Exercise
What is the main difference in age structure between the two countries?
In Ecuador, as in many developing countries, a high proportion of the population are young, whereas in Sweden, like most industrialised countries, older people comprise a greater proportion of the population.