Module 4: Standardization

Question 1

Mortality rates are great for examples of standardization because they are
commonly _____.

Answer 1

Standardized.

Question 2

_____ is the single most important predictor of mortality.

Answer 2

Age.

Question 3

What are “crude” mortality rates? What two things do they reflect?

Answer 3

Mortality rates as observed averaged over the population.

The force of mortality. Age composition.

Question 4

We want to remove the influence of the age composition when comparing mortality rates in different populations. Why, according to Patten?

Answer 4

Mortality rates are confounded by age. Age cannot be changed (unmodifiable) and its influence on mortality
is not interesting.

Question 5

What is confounding?

Answer 5

The intermixing of more and less interesting effects when populations are compared.

Question 6

By removing age in the comparison of mortality rates in different populations, we are saying what?

Answer 6

We accept (or do not particularly care about) the influence of age on mortality specifically. We accept the age
pattern of death.

Question 7

Age-stratification, or stratifying by age, means what?

Answer 7

We look at age-specific mortality rates for each population and compare the rates within the same group.

Question 8

What are three advantages of stratification?

Answer 8

Real, observed numbers.

Meaningful comparison of mortality rates across different populations, removing the influence of differences in the age composition.

Informative.

Question 9

What are two disadvantages of stratification?

Answer 9

Need to look at data table row by row.

Could encounter a small number issues (small cells in specific rows, random chance, etc.).

Question 10

All forms of standardization require what population?

Answer 10

“Standard” population that we use as a benchmark to study populations we are interested in (comparator populations).

Question 11

Suppose we are comparing mortality rates of Population A and B. Direct standardization asks what two questions?

Answer 11

What would be the expected mortality in the standard population if it
had the mortality experience of Population A?

What would be the expected mortality in the standard population if it
had the mortality experience of Population B?

Question 12

Patten recommends using which groups as a standard population? Why?

Answer 12

National male and female populations.

A standard population should make for a meaningful comparison itself, it should be “roughly similar” to the populations being standardized.

Question 13

Mortality rates calculated through direct standardization are age-adjusted. Importantly, what else are these mortality rates?

Answer 13

Hypothetical. They are not the actual mortality rate we observe, so are used for comparison.

Question 14

Indirect standardization is always pair-wise. What does this mean?

Answer 14

Population A compared to a standard population.

Question 15

Indirect standardization asks what two questions?

Answer 15

What would be the expected mortality in Population A if it had the mortality experience of the standard population?

How would this expected mortality rate compare to the observed mortality rate?

Question 16

How is the standardized mortality ratio calculated?

Answer 16

Observed number of deaths / Expected number of deaths

Question 17

Interpret an SMR = 1; SMR > 1; SMR < 1.

Answer 17

SMR = 1: No elevated risk of mortality for the comparator population.

SMR > 1: Elevated risk of mortality for the comparator population.

SMR < 1: Reduced risk of mortality for the comparator population.

Question 18

What is the healthy worker effect?

Answer 18

People who work are healthier than general population.

Question 19

Making meaningful comparisons across populations means we try to
remove the influence of what? Provide an example.

Answer 19

Of different distributions. E.g., age - this influence is not meaningful, we don’t really care about death caused by age itself.