CPH EXAM TESTBANK NEWEST UPDATE
Latest Question and Answer (2026/2027)
| Detailed Rationales | A+ Verified
• Adjusted rate . CORRECT ANSWER: Effects of differences in composition of pops
being compared have been minimized by statistical methods.
ex: regression analysis and strandardization
-often used on rates or relative risks
• Ecological Fallacy . CORRECT ANSWER: Bias that may occur because an
association observed between variables or an aggregate level does not represent
the association that exists at an individual level
• Confidence Interval . CORRECT ANSWER: 95% confident that the true value of a
variable is contained within the interval.
-used to account for sampling variability
-it is a point estimate +_ margin of error, where the point estimate is the best
estimate of teh unknown parameter and the margin of error is the product of the
confidence level and the standard error.
if a 95% CI for the differences in mean does not include 0 (the null value) then
there is eveidence of a statistically significant difference at sigma=0.05
• Clinical Trial Phases . CORRECT ANSWER: 1. Safety and Pharmacologic profiles
2. pilot efficacy studies
3. extensive clinical trials
,4. after the FDA approves, look at specific effects to establish incidence of adverse
reactions, etc. longterm use effects.
• interpretation of studies . CORRECT ANSWER: temporality: cause precedes
effect
Specificity: important in assessing the possibility of biases.
Consistency: several studies showing similar results. homogeneity statistically.
• Confounders . CORRECT ANSWER: -non-causal association between exposure
and outcome as a result of a third variable.
-distortion of effect by other factors
-must be related to exposure AND outcome
-not an intermediate variable on causal pathway
• Controlling for confounders . CORRECT ANSWER: before data collection:
random collection, individual matching, frequency matching
After data collection: direct adjustment, indirect adjustment, mantel-haenszel,
regression techniques
• Quality Assurance vs. Quality Control . CORRECT ANSWER: QA: ensure quality
before data collection
QC: monitor and maintain quality during study
• reliability vs. validity . CORRECT ANSWER: R: precision, reproducibility
V: accuracy, absence of bias
,• systematic error . CORRECT ANSWER: (lack of validity) if there's a difference
between what is actually being estimated and what is intended to be measured.
Increasing sample size doesn't help.
• Random Error . CORRECT ANSWER: (lack of precision) occurs, but increasing
sample size helps.
• RCT studies . CORRECT ANSWER: Tests efficacy or effectiveness of healthcare
services. random allocation of participants to different treatments. Includes
blinding, placebo. gold standard for evidence.
• Community Intervention/cluster RCT . CORRECT ANSWER: community-wide
basis or groupwide
• Case-Crossover RCT design . CORRECT ANSWER: -cases serve as their own
control
-exposure has transient effect
• Cross Sectional Studies . CORRECT ANSWER: SNAPSHOT! at a single point in
time. tells the prevalence and association. causation cannot be implied. a study
that examines the relationship between diseases and other variables as they exist
in a defined population at one particular time.
• Matching . CORRECT ANSWER: used to make cases and controls as similar as
possible to avoid confounding. ex: race, gender, age. +Maybe the only way to
control confounding. increases statistical power, straightforward. -requires use of
special analytical techniques, residual confounding can occur if you match
continuous variables by category.
, • types of matching . CORRECT ANSWER: individual matching: case and control
matched individually
frequency matching: a group of controls
Minimum Euclidean Distance measure: match to closest person.
• Cohort Studies . CORRECT ANSWER: RISK RATIO, RELATIVE RISK, INCIDENCE
RATE, RATE RATIO
-rare exposures
-group of subjects who shared experiences during a particular time. Determines if
incidence is related to exposure.
• Concurrent/longitudinal cohort studies . CORRECT ANSWER: starts now (with a
baseline exam) and goes into future. expensive and time intensive.
• non-concurrent/retrospective cohort studies . CORRECT ANSWER: assembled in
past based on existing records. faster and quicker, but records can be limited or
biased. follow up can be hard.
• Prevalence of disease . CORRECT ANSWER: measure of the burden of disease in
a community (new and existing cases). the number of events in a given population
at a designated time.
-obscures causal relationships
• point prevalence . CORRECT ANSWER: -proportion of pop that is diseased
during a single point of time.
-at a specific point in time
Latest Question and Answer (2026/2027)
| Detailed Rationales | A+ Verified
• Adjusted rate . CORRECT ANSWER: Effects of differences in composition of pops
being compared have been minimized by statistical methods.
ex: regression analysis and strandardization
-often used on rates or relative risks
• Ecological Fallacy . CORRECT ANSWER: Bias that may occur because an
association observed between variables or an aggregate level does not represent
the association that exists at an individual level
• Confidence Interval . CORRECT ANSWER: 95% confident that the true value of a
variable is contained within the interval.
-used to account for sampling variability
-it is a point estimate +_ margin of error, where the point estimate is the best
estimate of teh unknown parameter and the margin of error is the product of the
confidence level and the standard error.
if a 95% CI for the differences in mean does not include 0 (the null value) then
there is eveidence of a statistically significant difference at sigma=0.05
• Clinical Trial Phases . CORRECT ANSWER: 1. Safety and Pharmacologic profiles
2. pilot efficacy studies
3. extensive clinical trials
,4. after the FDA approves, look at specific effects to establish incidence of adverse
reactions, etc. longterm use effects.
• interpretation of studies . CORRECT ANSWER: temporality: cause precedes
effect
Specificity: important in assessing the possibility of biases.
Consistency: several studies showing similar results. homogeneity statistically.
• Confounders . CORRECT ANSWER: -non-causal association between exposure
and outcome as a result of a third variable.
-distortion of effect by other factors
-must be related to exposure AND outcome
-not an intermediate variable on causal pathway
• Controlling for confounders . CORRECT ANSWER: before data collection:
random collection, individual matching, frequency matching
After data collection: direct adjustment, indirect adjustment, mantel-haenszel,
regression techniques
• Quality Assurance vs. Quality Control . CORRECT ANSWER: QA: ensure quality
before data collection
QC: monitor and maintain quality during study
• reliability vs. validity . CORRECT ANSWER: R: precision, reproducibility
V: accuracy, absence of bias
,• systematic error . CORRECT ANSWER: (lack of validity) if there's a difference
between what is actually being estimated and what is intended to be measured.
Increasing sample size doesn't help.
• Random Error . CORRECT ANSWER: (lack of precision) occurs, but increasing
sample size helps.
• RCT studies . CORRECT ANSWER: Tests efficacy or effectiveness of healthcare
services. random allocation of participants to different treatments. Includes
blinding, placebo. gold standard for evidence.
• Community Intervention/cluster RCT . CORRECT ANSWER: community-wide
basis or groupwide
• Case-Crossover RCT design . CORRECT ANSWER: -cases serve as their own
control
-exposure has transient effect
• Cross Sectional Studies . CORRECT ANSWER: SNAPSHOT! at a single point in
time. tells the prevalence and association. causation cannot be implied. a study
that examines the relationship between diseases and other variables as they exist
in a defined population at one particular time.
• Matching . CORRECT ANSWER: used to make cases and controls as similar as
possible to avoid confounding. ex: race, gender, age. +Maybe the only way to
control confounding. increases statistical power, straightforward. -requires use of
special analytical techniques, residual confounding can occur if you match
continuous variables by category.
, • types of matching . CORRECT ANSWER: individual matching: case and control
matched individually
frequency matching: a group of controls
Minimum Euclidean Distance measure: match to closest person.
• Cohort Studies . CORRECT ANSWER: RISK RATIO, RELATIVE RISK, INCIDENCE
RATE, RATE RATIO
-rare exposures
-group of subjects who shared experiences during a particular time. Determines if
incidence is related to exposure.
• Concurrent/longitudinal cohort studies . CORRECT ANSWER: starts now (with a
baseline exam) and goes into future. expensive and time intensive.
• non-concurrent/retrospective cohort studies . CORRECT ANSWER: assembled in
past based on existing records. faster and quicker, but records can be limited or
biased. follow up can be hard.
• Prevalence of disease . CORRECT ANSWER: measure of the burden of disease in
a community (new and existing cases). the number of events in a given population
at a designated time.
-obscures causal relationships
• point prevalence . CORRECT ANSWER: -proportion of pop that is diseased
during a single point of time.
-at a specific point in time
