Population medicine and epidemiology

Question 1

5 objectives of epidemiology

Answer 1

1. determination of the origin of a disease whose cause is unknown
2. investigation and control of a disease whose cause is initially unknown
3. acquisition of information on the ecology and natural history of a disease
4. planning an monitoring of disease control programmes
5. assessment of the economic effects of a disease and of its control

Question 2

Evans postulates

Answer 2

1. the proportion of individuals with the disease should be significantly higher in those exposed to the supposed cause than those who are not
2. exposure to supposed cause should be more commonly seen in those with than without the disease
3. number of new cases of disease should be significantly higher in those exposed to the supposed cause
4. disease should follow exposure to the supposed cause with a distribution of incubation periods on bell shaped curve
5. spectrum of host responses
6. measurable host response
7. experimental reproduction of disease
8. elimination or modification of supposed cause should decrease frequency
9. prevention or modification of the hosts response should decrease/eliminate disease
10. all relationships and associations should be biologically and epidemiologically credible

Question 3

Prevalence equation

Answer 3

P = number of individuals having a disease at a particular point in time / number of individuals in the population at risk at that point in time

Question 4

Cumulative incidence equation

Answer 4

CI = number of individuals that become diseases during a particular period / number of healthy individuals in the population at the beginning of that period