Basic measures and methods in epidemiological studies

Question 1

What are the four aspects of epidemiology?

Answer 1

causation of disease
natural history of disease
health status of population
evaluating interventions

Question 2

Define Prevalence and incidence

Answer 2

Prevalence: the number of people in the population with a disease or condition

incidence: the number of people who develop a disease or condition within a specified period of time

Question 3

What is the equation of prevalence?

Answer 3

Prevalence (P) = (number of people with disease)/ ( number of people in whole population)

Question 4

What is the equation for incidence?

Answer 4

Incidence (I) = (number of people who develop a disease)/ (person time at risk)

Question 5

What is the equation for cumulative incidence?

Answer 5

CI = number who develop disease/ number at risk over specified time

Question 6

define crude mortality rate

Answer 6

number of deaths in specified period/ average total pop during the period

Question 7

Define risk

Answer 7

the probability of an event

Question 8

define odds

Answer 8

the probability of disease to the probability of not disease

Question 9

Define relative risk and give the equation

Answer 9

Risk of developing disease in people who are exposed compared to the risk of people who are not exposed

proportion who develop disease in exposed pop/ proportion who develop disease in unexposed pop

Question 10

Define odds ratio and give the equation

Answer 10

odds of having a characteristic in people with a disease to the odds of characteristic in those without

odds of exposed diseased people/ odds of exposed in disease free people