CPH FINAL PAPER 2026 QUESTIONS WITH
ANSWERS GRADED A+
◉ Adjusted rate. 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. 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. 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. 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. Answer: temporality: cause precedes effect
Specificity: important in assessing the possibility of biases.
Consistency: several studies showing similar results. homogeneity
statistically.
◉ Confounders. 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. 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. Answer: QA: ensure quality
before data collection
,QC: monitor and maintain quality during study
◉ reliability vs. validity. Answer: R: precision, reproducibility
V: accuracy, absence of bias
◉ systematic error. 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. Answer: (lack of precision) occurs, but increasing
sample size helps.
◉ RCT studies. 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. Answer: community-wide basis
or groupwide
◉ Case-Crossover RCT design. Answer: -cases serve as their own
control
-exposure has transient effect
, ◉ Cross Sectional Studies. 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. 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. Answer: individual matching: case and control
matched individually
frequency matching: a group of controls
Minimum Euclidean Distance measure: match to closest person.
◉ Cohort Studies. 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. Answer: starts now (with a
baseline exam) and goes into future. expensive and time intensive.
ANSWERS GRADED A+
◉ Adjusted rate. 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. 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. 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. 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. Answer: temporality: cause precedes effect
Specificity: important in assessing the possibility of biases.
Consistency: several studies showing similar results. homogeneity
statistically.
◉ Confounders. 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. 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. Answer: QA: ensure quality
before data collection
,QC: monitor and maintain quality during study
◉ reliability vs. validity. Answer: R: precision, reproducibility
V: accuracy, absence of bias
◉ systematic error. 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. Answer: (lack of precision) occurs, but increasing
sample size helps.
◉ RCT studies. 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. Answer: community-wide basis
or groupwide
◉ Case-Crossover RCT design. Answer: -cases serve as their own
control
-exposure has transient effect
, ◉ Cross Sectional Studies. 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. 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. Answer: individual matching: case and control
matched individually
frequency matching: a group of controls
Minimum Euclidean Distance measure: match to closest person.
◉ Cohort Studies. 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. Answer: starts now (with a
baseline exam) and goes into future. expensive and time intensive.
