NBME CBSE REAL EXAMINATION TEST PAPER
COMPLETE QUESTIONS AND VERIFIED
ANSWERS ELITE REVIEW 2026
▶ 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
▶ What is the per-protocol analysis? Answer:Excluding subjects who
did not complete the originally assigned treatment
▶ What is the disadvantage of per-protocol analysis? Answer:Increases
the risk of bias
▶ What are the five phases of clinical trials? Answer:Preclinical, Phase
0, Phase 1, Phase 2, Phase 3, Phase 4
COMPLETE QUESTIONS AND VERIFIED
ANSWERS ELITE REVIEW 2026
▶ 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
▶ What is the per-protocol analysis? Answer:Excluding subjects who
did not complete the originally assigned treatment
▶ What is the disadvantage of per-protocol analysis? Answer:Increases
the risk of bias
▶ What are the five phases of clinical trials? Answer:Preclinical, Phase
0, Phase 1, Phase 2, Phase 3, Phase 4
