NBME CBSE: PUBLIC HEALTH SCIENCES PT. 1 QUESTIONS AND
CORRECT DETAILED ANSWERS NEWEST UPDATE (usmle step 1)
MEDICAL EXAMINATION.
QUESTION
A medical researcher is preparing a manuscript describing the clinical findings of
several patients who presented with a rare disease. The researcher is summarizing
the signs, symptoms, and outcomes of these patients in a descriptive manner.
What type of study design is being used when a researcher describes the clinical
findings and symptoms for several patients with the same diagnosis, treatment, or
outcome?
CORRECT ANSWER: Description of clinical findings/symptoms for several
patients with the same diagnosis, treatment, or outcome.
Expert Rationale
A case series is a descriptive study that reports on a collection of individual
patients who share a common disease, exposure, or treatment. It provides a
detailed account of the clinical presentation, course, and outcomes of these
patients. Case series are often the first step in identifying new diseases or adverse
effects of treatments. They are valuable for generating hypotheses but lack a
control group, so they cannot establish causal relationships. The description of
clinical findings for several patients with the same diagnosis is the hallmark of a
case series.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Epidemiology and Biostatistics
MSC: NCLEX: Physiological Integrity
WITHOUT MULTICHOICES
,QUESTION
A public health researcher is designing a study to assess the current prevalence of
a disease and its associated risk factors in a defined population at a single point in
time. The researcher plans to survey a representative sample of the population to
gather data on both the disease and potential exposures simultaneously. What
type of study design is being used to assess the frequency of disease and risk-
related factors in the present?
CORRECT ANSWER: Assesses the frequency of disease and risk-related factors in
the present.
Expert Rationale
A cross-sectional study is an observational study that measures the prevalence of
a disease (or condition) and the prevalence of potential risk factors or exposures
at a single point in time. It provides a "snapshot" of the health status of a
population. Cross-sectional studies are useful for estimating the burden of
disease, identifying associated factors, and generating hypotheses. However,
because exposure and outcome are measured simultaneously, they cannot
establish temporal relationships (i.e., whether the exposure preceded the disease)
or causality.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Epidemiology and Biostatistics
MSC: NCLEX: Physiological Integrity
WITHOUT MULTICHOICES
QUESTION
A researcher is investigating a potential link between a rare exposure and a
specific disease. The researcher identifies a group of individuals with the disease
,(cases) and a group of individuals without the disease (controls) and then
retrospectively examines their histories to determine the frequency of the
exposure. What type of study design is being used to retrospectively compare a
group of people with a disease to a group without the disease to determine if the
odds of prior exposure or risk factor differ?
CORRECT 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.
Expert Rationale
A case-control study is an observational study that starts with the identification of
individuals with a disease (cases) and a comparable group without the disease
(controls). The researcher then looks back in time (retrospectively) to assess the
frequency of exposure to a potential risk factor in both groups. The measure of
association in a case-control study is the odds ratio (OR), which estimates the
odds of exposure among cases compared to controls. Case-control studies are
efficient for studying rare diseases and can be conducted relatively quickly and
inexpensively.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Epidemiology and Biostatistics
MSC: NCLEX: Physiological Integrity
WITHOUT MULTICHOICES
QUESTION
A researcher is interested in studying the long-term effects of a specific
occupational exposure on the development of a chronic disease. The researcher
identifies a group of workers with the exposure and a group of workers without
, the exposure and follows them over time to compare the incidence of the disease.
What type of study design is being used to compare a group of people with a
given exposure or risk factor to a group without exposure to determine if the
exposure or risk factor is associated with the later development of disease?
CORRECT 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.
Expert Rationale
A cohort study is an observational study that follows a group of individuals (a
cohort) over time to compare the incidence of a disease or outcome between
those who are exposed to a risk factor and those who are not. Cohort studies are
prospective (or sometimes retrospective) and provide strong evidence for causal
relationships because exposure is measured before the outcome occurs. The
measure of association in a cohort study is the relative risk (RR). Cohort studies
are particularly useful for studying the effects of rare exposures and for
establishing temporal relationships.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Epidemiology and Biostatistics
MSC: NCLEX: Physiological Integrity
WITHOUT MULTICHOICES
QUESTION
A geneticist is studying the heritability of a complex disease by comparing the
concordance rates of the disease in monozygotic (identical) twins and dizygotic
(fraternal) twins. The researcher is interested in determining the relative
contributions of genetic and environmental factors. What type of study design is
CORRECT DETAILED ANSWERS NEWEST UPDATE (usmle step 1)
MEDICAL EXAMINATION.
QUESTION
A medical researcher is preparing a manuscript describing the clinical findings of
several patients who presented with a rare disease. The researcher is summarizing
the signs, symptoms, and outcomes of these patients in a descriptive manner.
What type of study design is being used when a researcher describes the clinical
findings and symptoms for several patients with the same diagnosis, treatment, or
outcome?
CORRECT ANSWER: Description of clinical findings/symptoms for several
patients with the same diagnosis, treatment, or outcome.
Expert Rationale
A case series is a descriptive study that reports on a collection of individual
patients who share a common disease, exposure, or treatment. It provides a
detailed account of the clinical presentation, course, and outcomes of these
patients. Case series are often the first step in identifying new diseases or adverse
effects of treatments. They are valuable for generating hypotheses but lack a
control group, so they cannot establish causal relationships. The description of
clinical findings for several patients with the same diagnosis is the hallmark of a
case series.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Epidemiology and Biostatistics
MSC: NCLEX: Physiological Integrity
WITHOUT MULTICHOICES
,QUESTION
A public health researcher is designing a study to assess the current prevalence of
a disease and its associated risk factors in a defined population at a single point in
time. The researcher plans to survey a representative sample of the population to
gather data on both the disease and potential exposures simultaneously. What
type of study design is being used to assess the frequency of disease and risk-
related factors in the present?
CORRECT ANSWER: Assesses the frequency of disease and risk-related factors in
the present.
Expert Rationale
A cross-sectional study is an observational study that measures the prevalence of
a disease (or condition) and the prevalence of potential risk factors or exposures
at a single point in time. It provides a "snapshot" of the health status of a
population. Cross-sectional studies are useful for estimating the burden of
disease, identifying associated factors, and generating hypotheses. However,
because exposure and outcome are measured simultaneously, they cannot
establish temporal relationships (i.e., whether the exposure preceded the disease)
or causality.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Epidemiology and Biostatistics
MSC: NCLEX: Physiological Integrity
WITHOUT MULTICHOICES
QUESTION
A researcher is investigating a potential link between a rare exposure and a
specific disease. The researcher identifies a group of individuals with the disease
,(cases) and a group of individuals without the disease (controls) and then
retrospectively examines their histories to determine the frequency of the
exposure. What type of study design is being used to retrospectively compare a
group of people with a disease to a group without the disease to determine if the
odds of prior exposure or risk factor differ?
CORRECT 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.
Expert Rationale
A case-control study is an observational study that starts with the identification of
individuals with a disease (cases) and a comparable group without the disease
(controls). The researcher then looks back in time (retrospectively) to assess the
frequency of exposure to a potential risk factor in both groups. The measure of
association in a case-control study is the odds ratio (OR), which estimates the
odds of exposure among cases compared to controls. Case-control studies are
efficient for studying rare diseases and can be conducted relatively quickly and
inexpensively.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Epidemiology and Biostatistics
MSC: NCLEX: Physiological Integrity
WITHOUT MULTICHOICES
QUESTION
A researcher is interested in studying the long-term effects of a specific
occupational exposure on the development of a chronic disease. The researcher
identifies a group of workers with the exposure and a group of workers without
, the exposure and follows them over time to compare the incidence of the disease.
What type of study design is being used to compare a group of people with a
given exposure or risk factor to a group without exposure to determine if the
exposure or risk factor is associated with the later development of disease?
CORRECT 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.
Expert Rationale
A cohort study is an observational study that follows a group of individuals (a
cohort) over time to compare the incidence of a disease or outcome between
those who are exposed to a risk factor and those who are not. Cohort studies are
prospective (or sometimes retrospective) and provide strong evidence for causal
relationships because exposure is measured before the outcome occurs. The
measure of association in a cohort study is the relative risk (RR). Cohort studies
are particularly useful for studying the effects of rare exposures and for
establishing temporal relationships.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Epidemiology and Biostatistics
MSC: NCLEX: Physiological Integrity
WITHOUT MULTICHOICES
QUESTION
A geneticist is studying the heritability of a complex disease by comparing the
concordance rates of the disease in monozygotic (identical) twins and dizygotic
(fraternal) twins. The researcher is interested in determining the relative
contributions of genetic and environmental factors. What type of study design is
