Evidence Based Medicine Flashcards
What is the primary purpose of descriptive studies in clinical research?
To describe specific characteristics or experiences within a population.
Name three types of descriptive studies.
Case reports, case series, surveys, and qualitative research (e.g., interviews and focus groups).
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What are the main limitations of descriptive studies?
They lack a control group, may have sampling bias, and cannot establish causation.
What is the goal of analytical studies in clinical research?
To quantify the relationship between variables.
What are the two main categories of analytical studies?
Observational studies and interventional studies.
Describe the design of a case-control study.
Retrospective; compares a group with a condition (cases) to a similar group without the condition (controls) to identify risk factors.
What are the limitations of case-control studies?
They are subject to recall bias, lack randomization, and face challenges in finding suitable control groups. They also cannot prove causation.
What type of study follows participants forward in time to assess outcomes based on exposure?
Cohort study.
List two limitations of cohort studies.
They are inefficient for rare diseases or long-latency effects and cannot establish causation due to lack of randomization.
Why are randomized controlled trials (RCTs) considered high on the evidence hierarchy?
Because they control variables through randomization and blinding, reducing bias and confounding factors.
What are some control designs used in RCTs?
Placebo control, dose comparison control, active treatment control, and no treatment control.
What are some limitations of randomized controlled trials?
They are costly, time-consuming, may lack generalizability, and have limited clinical applicability to real-world settings.
Define “bias” in the context of clinical research.
Systematic deviation of study results from the ‘true’ results, caused by study design or conduct.
What is “confounding” in clinical studies?
When the effect of an intervention on an outcome is distorted by an outside factor related to both the population and the outcome.
Arrange the types of evidence from highest to lowest in the evidence hierarchy.
Randomized Controlled Trials (RCTs), Cohort Studies, Case-Control Studies, Descriptive Studies, and Expert Opinions.
