EPI5.6: STANDARDIZATION: SUMMARY STEPS FOR DIRECT STANDARDISATION
SUMMARY STEPS FOR DIRECT STANDARDISATION:
Calculate the age-specific rate for each age category in Populations 1 and 2.
Multiply these rates within each age category by the number of persons or person-years in this category in the standard or reference population.
Add up all these products.
Divide by the sum of all people or person-years in the reference or standard population to get the age standardised rates for index Populations 1 and 2 respectively.
Divide the standardised rates in index population 1 by that in index population 2. This is the Standardised Rate Ratio.