PP Flashcards
Quantitive vs qualitative
Quantitive
- objectivist
- single reality measured
- more mathematical analysis
- start with hypothesis (prior to the study)
Qualitative
- multiple realities measured
- constructivist
- more descriptive analysis
- ends with hypothesis
Examples of qualitative studies
- in - depth interviews
- focus group discussions
- participant observations
Examples of quantitative studies
- Cross-sectional studies
- Case-controlled studies
- Cohort studies
- Individually randomised controlled trials
- Cluster-randomised controlled trials
- Diagnostic accuracy studies
What case-control studies are used for?
- rare diseases
- outbreak investigations
What do we examine in case-control studies?
- Controls without the outcome/disease
- Cases with an outcome/disease
*look backwards: from outcome to exposure (risk factors)
What happens in cohort studies?
Compare the appearance of disease in people without measured risk factors vs people with risk factors
Exposure proceeds outcome
Aim: to compare the relationship of exposure to outcome
How to adjust for confoundings in case-control studies?
- Match cases and cohorts on recruitment -> age/sex
- Potentially not matched on other confounders
How to adjust for confounders in cohort studies?
Adjust for confounders in analysis
- Multivariable regression analysis
Bradford - Hill Criteria
Bradford - Hill → assesses if observed associations are causal
- Strength of association
- Consistency
- Specificity
- Temporality
- Biological gradient
- Plausibility
- Coherence
- Experiment
- Analogy
What’s internal validity?
What’s external validity?
Formulas for specificity and sensitivity
Formulas for
- positive predictive value
- negative predictive value
Risk ratio vs absolute risk
What’s Geoffrey Rose’s population strategy?
