Measuring Disease In Populations

Question 1

Define prevalence rate

Answer 1

The number of people affected by a disease (the burden of disease)

Question 2

What is the incidence rate useful for?

Answer 2

Useful when monitoring epidemics, when disease is of short duration, and for monitoring effects of prevention programs

Question 3

What is prevalence rate useful for?

Answer 3

Gives a measure of service requirements from a chronic condition

Question 4

Why are age and sex-based variation considered a nuisance?

Answer 4

As they are strong determinants of disease yet not useful for prevention.

Question 5

What is a standardised mortality ratio?

Answer 5

Compares the level of morbidity exposed to the level of morbidity expected if age-specific morbidity rates were applied to the study population.

Question 6

What are the values given by a SMR and what do they mean?

Answer 6

100=same risk in the study population as the reference population
>100=excess risk in study population compared to reference population

Question 7

Define Incidence Rate

Answer 7

The number of new cases of an illness that occurred

Question 8

How do you calculate an incidence rate?

Answer 8

New events/(person x time (years) )

Question 9

How do you calculate an incidence rate ratio?

Answer 9

(Rate b (exposed)/ rate a (unexposed))

Question 10

How do you calculate a point prevalence?

Answer 10

The number of people suffering from disease/ the reference population