How do you do direct standardization?
Procedure for direct standardization Multiply the age-specific mortality rates of the other population under study to the number of persons in each age group of the standard population. By this way, you will get the expected deaths for each age group of each population.
Why is direct standardization done?
Direct standardization is used when the number of events or the mortality rates in each age group within the population, is known, whereas indirect standardization is used when the number of events or the mortality rates in each age group within the population is not known.
How is standardisation achieved in an epidemiological study?
This is achieved by using the methods of standardisation. There are two methods of standardisation commonly used in epidemiological studies, and these are characterized by whether the standard used is a population distribution (direct method) or a set of specific rates (indirect method).
When to use indirect or direct standardisation in a study?
Indirect standardisation is more appropriate for use in studies with small numbers or when the rates are unstable. As the choice of a standard population will affect the comparison between populations, it should always be stated clearly which standard population has been applied.
How are standardized mortality ratios used in epidemiology?
Standardized Mortality Ratios are frequently used in epidemiology to compare different study groups, because they are easy to calculate and also because they provide an estimate of the relative risk between the standard population and the population under study.
Where does the standard population come from in a study?
The standard population may come from the study population (sum or average for example). In this case however, it is important to ensure that the populations do not differ in size, since a larger population may unduly influence the adjusted rates.