2. Standardisation

Question 1

What is the (crude) mortality rate? Formula?

Answer 1

Overall incidence/death rate in a population without taking any other features of the population into account. number of deaths per 1000/years

Question 2

What is (direct) standardisation?

Answer 2

calculating the overall incidence or mortality rate that you would have expected to find in a ‘standard’ population if it had the same (age-)specific rates as your study population

Question 3

Crude mortality rates cannot be compared between different countries because…

Answer 3

They are not adjusted for anything. Factors are not taken into account.

Question 4

Age-adjusted mortality rates can be compared, as long as..

Answer 4

they are standardized to the same standard population and the denominator is the same

Question 5

What is the age-adjusted mortality rate?

Answer 5

(expected) total no of deaths/1000 people.

Question 6

What measure is used to compare age-adjusted mortality rates with direct standardization? Formula?

Answer 6

CMF: Comparative mortality figure. = standardized mortality rate/mortality rate of x (standard population or other population you want to compare it to).

Question 7

What is needed for direct standardization?

Answer 7

Mortality rates of your population of interest, (age) distribution of a standard population

Question 8

How to calculate direct standardization/CMF?

Answer 8

1. Calculate exp. Death rates (mortality rate * standard pop n)
2. Sum up total exp deaths
3. Total exp deaths/total standard population (per 1000) = CMF

Question 9

When is direct standardization not so useful?

Answer 9

When the population is very small/when one age group is very underrepresented

Question 10

What is the outcome measure of indirect standardization? Formula?

Answer 10

SMR (standardized mortality ratio), obs deaths (pop. of interest)/expected deaths (pop of interest, when applyinf mortality rates of standard population)

Question 11

What is needed for indirect standardization?

Answer 11

1. Age-specific rates in standard population
2. Age distribution of population of interest
3. Total no of cases in population of interest

Question 12

What is indirect standardization?

Answer 12

calculate the number of cases we would have expected to see in our study population if it had the same age-specific rates of disease as a standard population

Question 13

What is direct standardization?

Answer 13

calculate the overall rate that we would see in a ‘standard’ population if it had the same age-specific rates of disease as our study population

Question 14

What is the PMR? When is it used? How is it calculated?

Answer 14

The proportional mortality ratio.
= Measure of the relative importance of a particular cause of death in a given population.
Is used when there is insufficient information to calculate an SMR (usually because information is available only about those who have died, so it is not possible to calculate mortality rates).

= Proportion of deaths due to a specific cause in a group of interest /proportion of deaths due to the same cause in a comparison group (often x100)

Question 15

Why can two SIR/SMR (ratio)s, deriving from indirect standardisation) not be directly compared?

Answer 15

Because they are both calculated relative to a seperate third population. Each population of interests standardized rate is based on its own age distribution

Question 16

When can two SIR/SMR (ratio)s, deriving from indirect standardisation) be compared?

Answer 16

As long as the populations have similar age distributions

Question 17

What is the CFR? What is it used for?

Answer 17

The case–fatality ratio (CFR) = the proportion of people with a given disease or condition who die from it in a given period. Direct assessment of the effectiveness of an intervention.

Question 18

What is the survival rate?

Answer 18

The proportion of patients who are still alive a specified number of years after diagnosis.

Question 19

IR is never a..

Answer 19

%

Question 20

What is prevalence formula with incidence and duration if disease is not rare?

Answer 20

p/(p-1)~I x D

Question 21

!

Answer 21

Bij CMF deel je de expected deaths door de STANDARD N populatie

Question 22

How do you calculate the crude rate?

Answer 22

CRUDE RATE = Sum of (age-specific rate x proportion of pop in that age category)

Question 23

QALY =

Answer 23

Years lived in full health + years lived with disability