Standardization

Standardization is a classic epidemiologic method for comparison of rates. For example, we often use standardized mortality ratios to compare the death rates of a study population with that of a standard population because of the difference in age structures and age-specific rates in the two populations being compared. Standardization is used as a method of removing the effect of potential confounders. There are two methods of standardization: direct method and indirect method. The direct method of standardization is preferred over the indirect method because the latter does not always guarantee to achieve standardization. This chapter will provide steps for calculating both direct and indirect standardization methods with practical examples and exercises.