semester 2 session 2 epidemiological study designs

Question 1

epidemiology

Answer 1

study of distribution and determinants of health - related states or event events in specified populations and the application of this study to the control of health populations

Question 2

analytical studies

Answer 2

• 2+ groups studied for comparison
• create a hypothesis regarding on an exposure possibling causing an outcome or not
• thenn you accept or reject hypothesis

Question 3

surveillence and descriptive studies

Answer 3

• studies one group
• no explicit hypothesis
• then at the end create a hypothesis regarding cause and effect

Question 4

ecological study

Answer 4

• identify groups to study (women/men ro countries)
• gather date
• define exposure and outcome
• decide if its catagorical or continous data

Question 5

problems with ecological studies

Answer 5

• measurement variation ( different countries may measure differently)
• confounding factors (effects the independent and dependent variable)
• chance - random error

Question 6

cross sectional study

Answer 6

• series of surveys
• normally for individuals
• happening at the current time

Question 7

issues with cross sectional studies

Answer 7

• sampling bias
• participant bias
• chance error
• confounding factors

Question 8

case - control studies

Answer 8

• looks at whats happened previosuly
• comparing cases against a control group
• compare against illness (who has and who hasnt)
• compare exposures / differences in their lives

Question 9

issues with case control

Answer 9

• selection bias - does control represent the study population
• information bias = non- differential misclassification (random error)?
• differential bias - systematic error, assesor bias problem with data collection
• confounding
• chance

Question 10

cohort study

Answer 10

• perspective - looks forward in time (how exposure effects rate of getting the disease)
• selects groups of people depending on the exposure
• compare incidence rates between exposure and disease
• can do historical collection where you collect data from the past and compare

Question 11

advantage for case controlled study

Answer 11

• good for rare diseases
• cheap
• quick
• can study multiple exposures for one outcome

Question 12

advantages for case controlled study

Answer 12

• better at studing a range of ouctomes from one exposure
• establishes that exposure precedes outcome
• better for conditions that fluctuate with age

Question 13

disadvantage for case controlled study

Answer 13

• people drop out = differential loss and surviver bias
• information bias
• confounding factors
• chance / random error
• expensive
• long time