NBME CBSE STEP 1 EXAM CERTIFICATION
EVALUATION TEST SCRIPT STUDY GUIDE
WITH SOLVED QUESTIONS
⩥ What is a cross-sectional study?
Answer: Assesses the frequency of disease and risk-related factors in the
present.
⩥ What is a case-control study?
Answer: Retrospectively compares a group of people with a disease to a
group without the disease to determine if odds of prior exposure/risk
factor differ.
⩥ What is a cohort study?
Answer: Compares a group of people with a given exposure/risk factor
to a group without exposure to determine if the exposure/risk factor is
associated with later development of disease.
⩥ What is a twin concordance study?
Answer: Compares the frequency with which both monozygotic twins vs
both dizygotic twins develop the same disease to measure heritability
and influence of environmental factors.
,⩥ What is an adoption study?
Answer: Compares behavioral traits/genetics in siblings raised by
biological vs adoptive parents to measure heritability and influence of
environmental factors.
⩥ What is an ecological study?
Answer: Compares the frequency of disease and risk-related factors
across populations to measure population data (not applicable to
individuals).
⩥ What is a clinic therapeutic trial?
Answer: An experimental study involving humans that compares the
benefits of two or more interventions.
⩥ What are the criteria for a high-quality clinical trial?
Answer: Randomized, controlled, and double-blinded
⩥ What is a crossover clinical trial?
Answer: Compares the effect of multiple treatments on a subject
⩥ What is the purpose of randomizing the order of treatments in a
crossover trial?
Answer: To avoid bias
, ⩥ What is a washout period in a crossover trial?
Answer: A period between treatments to eliminate any lingering effects
⩥ What is the advantage of using a crossover trial?
Answer: Subjects serve as their own controls
⩥ What is the intention-to-treat analysis?
Answer: Analyzing all subjects according to their original assigned
treatment
⩥ What is the purpose of intention-to-treat analysis?
Answer: To avoid bias from attrition, crossover, and noncompliance
⩥ What is the disadvantage of intention-to-treat analysis?
Answer: May dilute the true effects of the intervention
⩥ What is the as-treated analysis?
Answer: Analyzing subjects according to the treatment they actually
received
⩥ What is the disadvantage of as-treated analysis?
Answer: Increases the risk of bias
EVALUATION TEST SCRIPT STUDY GUIDE
WITH SOLVED QUESTIONS
⩥ What is a cross-sectional study?
Answer: Assesses the frequency of disease and risk-related factors in the
present.
⩥ What is a case-control study?
Answer: Retrospectively compares a group of people with a disease to a
group without the disease to determine if odds of prior exposure/risk
factor differ.
⩥ What is a cohort study?
Answer: Compares a group of people with a given exposure/risk factor
to a group without exposure to determine if the exposure/risk factor is
associated with later development of disease.
⩥ What is a twin concordance study?
Answer: Compares the frequency with which both monozygotic twins vs
both dizygotic twins develop the same disease to measure heritability
and influence of environmental factors.
,⩥ What is an adoption study?
Answer: Compares behavioral traits/genetics in siblings raised by
biological vs adoptive parents to measure heritability and influence of
environmental factors.
⩥ What is an ecological study?
Answer: Compares the frequency of disease and risk-related factors
across populations to measure population data (not applicable to
individuals).
⩥ What is a clinic therapeutic trial?
Answer: An experimental study involving humans that compares the
benefits of two or more interventions.
⩥ What are the criteria for a high-quality clinical trial?
Answer: Randomized, controlled, and double-blinded
⩥ What is a crossover clinical trial?
Answer: Compares the effect of multiple treatments on a subject
⩥ What is the purpose of randomizing the order of treatments in a
crossover trial?
Answer: To avoid bias
, ⩥ What is a washout period in a crossover trial?
Answer: A period between treatments to eliminate any lingering effects
⩥ What is the advantage of using a crossover trial?
Answer: Subjects serve as their own controls
⩥ What is the intention-to-treat analysis?
Answer: Analyzing all subjects according to their original assigned
treatment
⩥ What is the purpose of intention-to-treat analysis?
Answer: To avoid bias from attrition, crossover, and noncompliance
⩥ What is the disadvantage of intention-to-treat analysis?
Answer: May dilute the true effects of the intervention
⩥ What is the as-treated analysis?
Answer: Analyzing subjects according to the treatment they actually
received
⩥ What is the disadvantage of as-treated analysis?
Answer: Increases the risk of bias
