Module 12 Flashcards
what does analytic epidemiology examine?
the relationship between hypothesized causes and health outcomes
-why/how or cause and effect
- describes the DETERMINANTS of health-related states and events
-quantifies the association between exposures and outcomes to ID casual relationships
what are risk factors?
- factors or events associated with the disease or health state or event of interest
- are not necessarily direct causes of disease or injury but are associated with the development of the disease or injury
what are example of risk factors? (7)
- Poverty (persons living at 100% FPL)
- Neighborhood: physical and psychological barriers
- Race (self reported, race for addressing disparities related to various health risk factors)
- Education
- genetic
- hereditary
-environmental
Bradford Hill Criteria for Causation
- Strength of association
- Consistency
- Specificity
- Temporal relationship
- Biological gradient
- Plausibility
- Coherence
- Analogy
- Experimental evidence
define: risk
- A measure of disease frequency
- The probability that an event will occur
calculation of absolute risk
Absolute Risk = Number of people who get the disease during a designated period/
Population of interest at the start
of the designated time period
T/F: Absolute risk and incidence proportion are the same thing
true
Incidence proportion is the terminology used to describe _____
populations
Risk is the terminology used to describe ______
individuals
what is attributable risk?
- Attributable risk is the amount of disease that can be attributed to a specific exposure
***aka risk difference
what are risk ratios used to compare?
used to compare the occurrence of disease in one group with the occurrence of disease in another group
what are two common methods used to compare occurrences of diseases in groups?
- Commonly used measures are
- Risk Ratio or Relative Risk Ratio (RR)
- Odds Ratio (OR)
what is relative risk?
- Relative risk is a measure of association between the exposure to a particular factor and the risk of a particular disease or outcome
- it estimates the magnitude of the association between the exposure to a particular factor and the risk of a particular disease or outcome
- risk ratio or relative risk ratio is preferably used in cohort studies–> prospective studies
Interpretation of the Relative Risk Statistic: RR= 1
- Incidence of the outcome in the exposed group is equal to the risk in the non-exposed group
Interpretation of the Relative Risk Statistic: RR >1
- Incidence of the outcome in the exposed group is greater than the risk in the non-exposed group
Interpretation of the Relative Risk Statistic: RR <1
- Incidence in the outcome in the exposed group is lower than the risk in the non-exposed group
Interpretation of the Odds Ratio: OR=1
- Exposure to the factor does not affect the odds of the outcome
Interpretation of the Odds Ratio: OR >1
- Exposure to the factor increases the odds of the outcome
Interpretation of the Odds Ratio: OR <1
- Exposure to the factor decreases the odds of the outcome
what is the level of evidence determined by?
- determined by the type of the study design used to obtain the evidence
- The study design influences that quality or ‘strength’ of the evidence produced
The hierarchy (or pyramid) of evidence ranks study designs: the designs on the top (2)
The designs on the top (meta-analyses, randomized controlled trials) provide the strongest or highest levels of evidence
The hierarchy (or pyramid) of evidence ranks study designs: the designs at the bottom (2)
The designs at the bottom (case reports, cross sectional studies) produce the weakest level of evidence
Study Designs in Epidemiology: systematic reviews (2)
- Meta-analyses
- Integrative reviews
Study Designs in Epidemiology: Experimental studies
- Randomized trials
- Non-randomized trials
Study Designs in Epidemiology: Observational studies
- Cohort studies
- Case-control studies
- Cross-sectional studies
Systematic Reviews: Meta-Analyses
-“Study of studies”
- Very powerful methodology
- Stringent criteria for inclusion in the analysis
- Quantitative analysis to combine and compare results of the studies
- Method used in Cochrane Reviews and AHRQ Reviews
Randomized Controlled or Clinical Trials
- Prospective study
- Experimental design
- Always has an intervention
- Randomization to treatment groups
- Control of the intervention
examples of Randomized Controlled or Clinical Trials
- Almost all studies of medications
- Most studies of devices
- Many studies of interventions
Nonrandomized Trials: Quasi-Experiments
- Prospective study
- Experimental design
- Always has an intervention
- Control of the intervention
- No randomization to treatment groups
- Comparison group may be different from the intervention group
Prospective Cohort Studies
- Prospective study
- Observational study
- No intervention
- Exposure are documented
- A group (cohort) of disease-free individuals is identified at one point in time and then followed over a period of time to determine whether the outcome (disease) occurs
Retrospective Cohort Studies
- Have a historical perspective
- Requires access to information about the subjects before the exposure to disease causing factors and before the onset of disease occurs
- Often able to accomplish this when there are comprehensive medical records
case-control studies
- Retrospective study design
- Studies people who already have the disease and looks backward at exposures
- Two groups of individuals are studied
- A group that has the disease under study (cases)
- A group that does not have the disease under study (controls)
- Their health information is then examined to determine whether there are risk factors that may be related to their current disease
what are cases ?
a group that has the disease under study
what are controls?
a group that does not have the disease under study
Cross-sectional Studies
- A study population is assessed at a single point in time
- Participants are asked about their current disease state and their exposures to certain factors
- Descriptive study
- Known as prevalence studies
- Very weak study design
Case Reports and Case Series
- Descriptive study design
- May generate hypotheses about causation
the bottom of the pyramid
- opinion
- experience
- theory
