Overview of epidemiology: concepts & study design Flashcards
What are the top 3 study designs in the hierarchy of evidence starting from the lower?
Non-randomised controlled trials
Randomised controlled trials
Systematic reviews / meta-analysis
Which category of study would be used to determine whether a new intervention works?
Experimental studies
What are the 2 types of experimental studies?
Randomised controlled trials
Non-randomised controlled trial
What category of study would be used to determine whether an exposure and outcome are associated with each other?
Analytical observational studies
What are the 4 types of analytical observational studies?
Cohort
Case-control
Cross-sectional studies
Ecological studies
What category of study would be used to determine the pattern of disease in a population?
Descriptive observational studies
What are the 3 types of descriptive observational studies?
Cross-sectional studies
Ecological studies
Case reports and case series
What are the 4 reasons for finding a specific result in study?
Truth
Chance
Bias
Confounding
In epidemiology, what is bias?
A systematic error in the design or conduct of a study that results in giving a result different from the truth
What are the 2 types of bias?
Selection bias
Information bias
What are the 4 types of selection bias.
Self-selection (volunteer) bias
Non-response bias
Healthy worker effect
Survival bias
What are the 4 types of information bias.
Recall bias
Interviewer bias
Social desirability bias
Attrition bias
What is a confounder?
A factor associated with both an exposure and an outcome that influences the association
A study finds that having a gym membership is associated with a lower risk of heart disease. Name two potential confounders.
Physical activity
Diet
Name and briefly describe any three Bradford Hill criteria.
Strength of association: larger effect sizes more likely to be causal
Dose-response relationship: if more exposure increases risk of outcome, more likely to be causal
Reversibility: removing exposure reduces the risk
In the Bradford-Hill criteria, what is meant by biological plausibility?
There is a demonstrable pathological mechanism by which the exposure can cause the outcome
