What is direct standardization?
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.
What is a directly Standardised rate?
Direct Standardization Standardized or adjusted rates are summary index measures for the purpose of comparison only; their magnitude has no intrinsic value. The choice of a reference or standard population is important; it must relate to the population under study naturally.
What are the methods of standardization?
There are two main standardization methods, characterized by whether the standard used is a population distribution (direct method) or a set of specific rates (indirect method).
How do you interpret indirect standardization?
Procedure for indirect standardization Multiply the number of people in each age group of the population(s) of interest by the age-specific mortality rate in the comparable age group of the reference population. Sum the total number of expected deaths for each population of interest.
What is the difference between direct standardization and indirect standardization?
The direct method of standardisation requires that the age-specific rates for all populations being studied are available and that a standard population is defined. Indirect standardisation is more appropriate for use in studies with small numbers or when the rates are unstable.
What is the difference between direct and indirect standardization?
In indirect standardisation, the weights applied to the standard age-specific rates depend on the age structure of the study populations. Direct standardisation requires that we know the age-specific rates of mortality (or morbidity) in all the populations under study.
How do you standardize by age?
To calculate the age-standardized mortality rate (ASMR), we must first calculate the age-specific (mortality) rates for each age group by dividing the number of deaths by the respective population, and then multiplying the resulting number by 100,000: Age-specific rate, 0 to 39 years.
What do you need to calculate for direct standardization?
Direct method of standardisation – calculation of the number of expected deaths for countries A and B applied to a standard population. (Here the rate is divided back by 1000 to give the basic rate; e.g. 1.2 becomes 0.0012 for the purposes of the formula.)
What is direct and indirect standardization?
What is the importance of standardization?
Standardization brings innovation and spreads knowledge Standardization also brings innovation, first because it provides structured methods and reliable data that save time in the innovation process and, second, because it makes it easier to disseminate groundbreaking ideas and knowledge about leading edge techniques.
Why are direct and indirect age standardization methods used?
How do you do direct age adjustment?
Calculation: To apply direct age-adjustment to a set of rates, the age-specific rate for each age group in the study population is multiplied by the appropriate weight in the standard population. The sum of these products is the directly age-adjusted, or age-standardized rate.
What are the two main methods of standardization?
There are two main standardization methods, characterized by whether the standard used is a population distribution (direct method) or a set of specific rates (indirect method). The two methods are presented below. Direct method In the direct standardization method, the rate that we would expect to find in the populations under study if they
How is the adjusted rate of standardization obtained?
The adjusted or “standardized” rate is obtained by dividing the total of expected cases by the standard population. An example is presented in box 2. An important step in the direct standardization method is the selection of a standard population.
How is the standardization method used in epidemiology?
In the direct standardization method, the rate that we would expect to find in the populations under study if they all had the same composition according to the variable which effect we wish to adjust or control (such as age, socioeconomic group, or other characteristics) is calculated.
Which is an example of the indirect method?
An example of adjustment using the indirect method is presented in box 4. Instead of using the structure of the standard population, we utilize its specific rates and apply them to the populations under comparison, previously stratified by the variable to be controlled. The total of expected cases is obtained this way.