Page 1 of 173
CPH EXAM 2 LATEST VERSIONS AND PRACTICE EXAM
NEWEST 2025 COMPLETE 500 QUESTIONS AND
CORRECT DETAILED ANSWERS WITH RATIONALES
(VERIFIED ANSWERS) |ALREADY GRADED A+
Attributable risk .....ANSWER.....Rate of disease in exposed
individuals that can be attributed to the exposure. Or the
proportion of all cases that can be attributed to a particular
exposure.
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
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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
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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
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-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.
CPH EXAM 2 LATEST VERSIONS AND PRACTICE EXAM
NEWEST 2025 COMPLETE 500 QUESTIONS AND
CORRECT DETAILED ANSWERS WITH RATIONALES
(VERIFIED ANSWERS) |ALREADY GRADED A+
Attributable risk .....ANSWER.....Rate of disease in exposed
individuals that can be attributed to the exposure. Or the
proportion of all cases that can be attributed to a particular
exposure.
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
,Page 2 of 173
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
,Page 3 of 173
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
, Page 4 of 173
-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.
