Week 1

Question 1

exposure

Answer 1

(risk factor or determinant)
any factor that may influence the outcome

Question 2

outcome

Answer 2

the disease, or event, or health related state under study

Question 3

define epidemiology

Answer 3

the study of the distribution/frequency of health related states and determinants in a population

Question 4

assumptions in epidemiology

Answer 4

disease does not occur at random
disease has casual and preventative factors

Question 5

role of epidemiology

Answer 5

to describe patterns of health and disease within populations
to interpret these differences
to apply results to public health practice
to evaluate effect of health-related interventions

Question 6

observational epidemiology

Answer 6

describes patterns of health and disease without intervening to change the factors which influence them

Question 7

what do descriptive studies measure

Answer 7

burden of illness

Question 8

examples of descriptive studies

Question 9

analytical study

Answer 9

can investigate risk factors for a disease or outcome (does not necessarily mean they are casual)

Question 10

interventional epidemiology

Answer 10

assess effect of a specific intervention
individual level or community

Question 11

case definition

Answer 11

method used to identify a case
boundaries of cases
unit analysis

Question 12

prevalence

Answer 12

number of existing cases in a population at a designated time
the number of affected persons present in the population divided by the number of people in the population

Question 13

prevalence calculation

Answer 13

no. of cases (people with disease)/
no. of people in the population

Question 14

point prevalence

Answer 14

the proportion of persons in a defined population that has the outcome under study at a specific point in time

Question 15

period prevalence

Answer 15

the proportion of persons in a defined population that has the outcome under study over a period of time

Question 16

when would you use period prevalence

Answer 16

measuring episodic conditions

Question 17

what is prevalence useful for

Answer 17

useful for assessing the burden of disease within a population
valuable for planning

Question 18

what is prevalence not useful for

Answer 18

determining what causes disease

Question 19

2 measures of incidence

Answer 19

risk and rate

Question 20

incidence risk

Answer 20

number of new cases in interval over the population initially at risk (mortality rates)

Question 21

incidence rate

Answer 21

number of new cases/ total person-time at risk

Question 22

when to use incidence risk

Answer 22

good for static populations

Question 23

when to use incidence rate

Answer 23

dynamic populations

Question 24

annual incidence

Answer 24

count deaths over calendar year (from routine data)
- use mid-year population as denominator
- expressed as cases per ….

Question 25

cumulative incidence

Answer 25

frequency of new cases over a specified period
denominator is no. of people at the start of the period
(events divided by initial population)

Question 26

potential problems with cumulative incidence

Answer 26

loss to follow up

Question 27

person years at risk

Answer 27

say there was 500 women being followed up over 2 years
500 for year 1
and say 300 died so for year 2 there was only 200 left
200 for year 2
total= 700
allows for loss to follow up

Question 28

what does annual incidence tell us

Answer 28

number of new cases over defined period
sensitive to changes in disease risk
more suitable for monitoring trends
less suitable for assessing burden of disease

Question 29

incidence vs prevalence

Answer 29

number of new cases vs number of existing cases

Question 30

age specific death rate

Answer 30

no. of people (in age group)

Question 31

prevalence in relation to incidence

Answer 31

prevalence = incidence x average disease duration
P= I x D