Disease frequency

Question 1

What is prevalence?

Answer 1

-Proportion of existing disease in the population at a given time

Question 2

What is incidence?

Answer 2

-Occurrence of new cases in a population at risk over time

Question 3

What is cumulative incidence? (incidence proportion)

Answer 3

• the number of new cases per person in the population over a defined period of time.

Question 4

What is incidence rate?

Answer 4

• the number of new cases per unit of time (“rate”).

Question 5

How do you calculate all 3?

Answer 5

Question 6

Look at patterns of prevalence and incidence.

Answer 6

Question 7

Look at what happens when a vaccine is introduced.

Answer 7

Question 8

Why do we need prevalence and incidence ?

Answer 8

-Prevalence : treatment is working
-Incidence: prevention is working
- think about a cure both in terms of preventing new diagnoses and treating existing diagnoses

Question 9

Incidence decreases but prevalence increased, why?

Answer 9

-Good public health
-Better management of risk factors
-Changes in healthcare i.e improved primary care
-Migration
-Lifestyle changes