Standardizations are arithmetic techniques for producing comparable epidemiological measures of structurally different populations.
There can be a difference in structure of the population for example in terms of age, sex and/or other characteristics. The standardization
by age occurs most often because the information is usually available and the age is important for the most health problems.
Use: Age standardizations based on a
standard population are often used at cancer registries to
compare morbidity or mortality rates. If there are different age structures in populations of different regions or in a population in one
region over time, mortality or morbidity rates is only limited. For interregional or inter-temporal comparability of their comparisons,
therefore, an age standardization is necessary.For this purpose the age structure of a reference population, the so-called standard
population, is assumed for the study population.
The age specific mortality or morbidity rates of the study population are weighted according to the age structure of the standard population.
Interpretation: By an age standardization, data of different years or regions are comparable, without distortion because of different
age structures. In the interpretation of age standardized morbidity or mortality rates it is important to notice that they are not real
information in the sense of empirically observable data.
In fact, they describe, how the mortality or morbidity rate would be, if the reference population and the standard population were equal,
thus abstracting from age structure effects.
Sources:
- www.rki.de
- Forschungs- und Entwicklungsgesellschaft Hessen; Hessisches Sozialministerium (Hrsg.) (2001): Indikatorenkatalog zum Hessischen Gesundheitsbericht 2001. Wiesbaden