Standardization and Life Tables

Question 1

What is the mortality rate?

Answer 1

How many people die in a population in a given time period.

Number of death/Time period.

Question 2

What is life expectancy?

Answer 2

How old are people when they die?

Cohort’s LE calculated by averaging age of members when they die.

Question 3

What is age-specific mortality rate?

Answer 3

Mortality rate within certain age groups.

Number of deaths/time period for a certain age group.

Question 4

What is cause-specific mortality rate?

Answer 4

Mortality rate for a specific cause for a population.

Number of death/time period for a population and cause of death is specific.

Question 5

What is the number one confounder between mortality and populations?

Answer 5

Age.

Question 6

How does age confound?

Answer 6

Age structure of a population varies by:

Geography
Time
Risk Factor

Question 7

How can we account for age?

Answer 7

Two ways:
Stratification (age-specific mortality)
Age adjustment (direct and indirect)

Question 8

What is direct age standarization?

Answer 8

Simulates two populations having same age structure.

Does not make age-specific mortality rates as comparable across populations since they would be the same.

Question 9

What is indirect standardization?

Answer 9

Simulates two populations having same age-specific mortality rates.

Makes age-specific death rates the same but you CANNOT compare age structures.

Question 10

How would you perform direct age adjustment?

Answer 10

Ex:

Unmarried men v married men.

Looks like death rate among married men is twice as much as unmarried men.

Step 1. Calculate age-specific and overall death rates.

Step 2. Create a standard population.

• Add the totals of the two populations to each other by age group. EX: Add group 1 20-30YO to group 2 20-30 YO
• This is standard population of unmarried and married men

Step 3. Apply death rate in each group to standard population to create “expected number of deaths” in each group
-Multiply death rate to standard population in each age group

Step 4. Calculate the age-standardized mortality rate

• Total number of expected deaths of population A/new total of standard population
• This results in AGE-STANDARDIZED MORTALITY RATE

Step 5. Compare the two

It allows us to equalize the number of people in age group.

Question 11

What is crude death rate?

Answer 11

Weighted average death rate across populations.
Calculated by:
SUM of [Each age specific death rate * number in each age group]
DIVIDED BY
Total population
It is also the number of death in the total population.

Question 12

How would you calculate indirect standardization?

Answer 12

Step 1.
Calculate expected number of deaths among group without death rate (Group B death rate)
-Use group A death rate and multiply by population for each age group in group B to get expected number of death in group B by age group.

Step 2.
Calculate the STANDARDIZED MORTALITY RATIO
-Number of recorded deaths in population B / number of expected deaths in population B

Step 3.
Interpret the standardized mortality ratio
-If SMR is 2.4 then the number of OBSERVED deaths among population B is 2.4 times higher than group A

Question 13

What are some pros of age-standardized mortality rates?

Answer 13

Powerful for comparing mortality in one population to another.

Question 14

Why is death a great indicator of health?

Answer 14

Case definition is straight-forward.
Everyone is at risk.
Information collected.

Question 15

When to use direct standardization?

Answer 15

When you have population size and number of deaths in each age group.

Question 16

When do you use indirect standardization?

Answer 16

When you have only death rate and not the size of the population.