Measures of Disease in Populations

Question 1

Describe Incidence, Recurrence, Prevalence, Mortality and Cure

Answer 1

Question 2

Is prevalence given as a value or proportion?

Answer 2

Proportion

e.g. 50% or 1 in 2

Question 3

How is risk calculated

Answer 3

Question 4

5000 People aged 45-54 without cardiovascular disease are identified. 10 years later, 147 of these have died fro or developed cardiovascular disease

Calculate Risk

Answer 4

147/5000 or 2.94%

Question 5

Total Person Time at Risk

Answer 5

Question 6

Total person time at risk for 15 people, in a study that lasted 20 years

Answer 6

300 Person Time at risk

Question 7

Incidence Rate

Answer 7

**THINK OF NUMBER OF NEW CASES ARISING IN GIVEN PERIOD IN SPECIFIED POPULATION

Question 8

Calculate Incidence Rate

Answer 8

2/45 OR 44 cases per 1,000

Question 9

Ecological Study

Answer 9

Studying associations on a population size sample

Data often taking from existing sources like census data, disease registry, etc

Question 10

Advantages of Ecological Studies

Answer 10

• Cheap/Quick
• Uses Existing Data
• No Ethical Approval Needed

Question 11

Limitations of Ecological Studies

Answer 11

• Confounding Variable
• Ecological Fallacy (Making assumption about individuals based on a population statistic)
• Can lead to generalisations of one population to be made about others incorrectly