lecture 17

Question 1

what are cross sectional studies

Answer 1

measures exposures and / or outcomes at one point in time

Question 2

what can cross sectional studies be used for

Answer 2

• prevalence
• has the prevalence changed over time
• can also be used to generate hypothesis
• to plan

Question 3

what does the triangle represent in the gate frame

Answer 3

contains the
- source = people who volunteered into the study

• sample = entered into the study

Question 4

what does the circle represent in the gate frame

Answer 4

• exposed group = those who have the exposure or potential risk factor that the study is looking for
• comparison group = those being compared

Question 5

what is the square represent in the gate frame

Answer 5

the outcome

Question 6

limitations of cross sectional study

Answer 6

• temporal sequencing
• only tell us about the prevalence
• not very good for studying rare outcomes or exposures
• not very good for assessing variable or transient exposure or outcomes

Question 7

what are the strengths of cross sectional cross studies

Answer 7

• can asses multiple exposures and outcomes at the same time
• depending on your research question… they may be the most appropriate study design
• can be less expensive than some other study designs
• relatively quick

Question 8

what are ecological studies used for

Answer 8

• to compare between populations
• to assess population level factors
• to consider hypothesis

Question 9

what are the limitations of ecological studies

Answer 9

• ecological fallacy (measure for the group, not the individual)
• can not control confounding
• can not show causation