Indirect standardisation (cont.)

In this example, let's say that we decide to take the age-specific mortality rates in Sweden as the standard. We need to calculate the expected number of deaths that would occur in Ecuador if the Swedish age-specific mortality rates applied to Ecuador's age structure.

We do this by taking the number of people in each age group of the study (Ecuadorian) population and multiplying it by the corresponding age-specific mortality rate in the standard (Swedish) population.

Exercise

Interaction In the table below, enter the missing values, then calculate the ratio of observed deaths to expected deaths in Ecuador (to two decimal places).

Age Population
(1000's) 		Observed Deaths (Ecuador) Age-specific rate (Sweden)
/ 1000 pyrs 		Expected No. of deaths
0-29 7,498 16,700 0.45
30-59 3,219 11,900 2.4 7726
60+ 742 36,100 42.4 31,461
Total 64,700  
Yes, the expected number of deaths in Ecuador according to this method is about 3374.
No, it looks like you have multiplied the observed deaths in Ecuador by the age-specific rate for Sweden. In fact you should have multiplied the population of Ecuador by the Swedish age-specific rate. This would give an answer of 3374 deaths.
That's right, the total expected number of deaths is 42 561. Now calculate the ratio of observed to expected deaths for Ecuador, to two decimal places.
Sorry, that's not right. You should have got an expected 3 374 deaths for the 0 - 29 age group, so the total expected number of deaths is 42561.

 

Observed Deaths (Ecuador) = 64700 =
            Expected Deaths            
      ?      
Yes, that is the correct answer. Now go on to the next page to find out more about this ratio.
Sorry, that's wrong. The ratio of total observed deaths to total expected deaths for this example is:

64 700 = 1.52
42 561

Please check that you got the right answers for the missing values in the table.