Standardization is an essential tool for the evaluation of public health status through comparing morbidity and mortality of two or more populations. It is beneficial for comparing mortality rates concerning the structure of both communities. While researchers can compare crude rates, they may be misleading due to being uninformative about the characteristics of the group under study (“Standardization,” n.d.).
Age and sex are the two most common variables that call for standardized rates. For instance, if Population A has a higher crude mortality rate from prostate cancer than Population B, one can conclude that Population A is more exposed to prostate cancer. However, this can be untrue, as Population A may consist mainly of males, while Population B could include mostly females. Therefore, obtaining standardized rates is crucial for receiving adequate epidemiology data.
There two primary methods of standardization that are applied under different circumstances depending on the set of available data. The direct method is useful for acquiring highly-precise epidemiological data for large groups of people when the rates are relatively stable (Martcheva, 2015). The approach can be used only when the characteristic-specific rates “for all populations being studied are available and that a standard population is defined” (“Standardization,” n.d., para. 27).
The indirect method is appropriate for small numbers, as it is less accurate due to the unavailability of characteristic-specific rates of a population (Martcheva, 2015). For instance, if the age-specific mortality rate of Population B cannot be obtained, the approach allows calculating how many deaths would be expected if it had the same age-specific mortality rates as Population A. In conclusion, both methods of standardization are essential instruments for acquiring precise epidemiological data.
References
Martcheva, M. (2015). An introduction to mathematical epidemiology. New York; Heidelberg: Springer.
Standardisation. (n.d.). Web.