AM2- Epidemiology and EBVM Exam With Complete
Solutions Latest Update
What is risk? - ANSWER Aka prevalence
The possibility of an event to happen
How is the risk measured? - ANSWER Number of outcome events
------------------------------× 100
Number of all events
What is relative risk/ risk ratio (RR)? - ANSWER -The ratio of two risks
-Comparison of the risks of two groups
-The measure of association calculated from a cohort study
-Divide one risk by the other to get an "x times more likely" statement
How is RR measured? - ANSWER Risk in group 1 (A/(A+B))
----------------------------
Risk in group 2 (C/(C+D))
What factors impact how valid a set of calculations are? - ANSWER Sample size
Lack of representation
Lack of random sampling
Bias
What is a point estimate? - ANSWER A single number computed from sample data used
to estimate a population parameter
,95% confidence interval - ANSWER The range within which we are 95% certain that the
true value or the measurement falls
Measures reliability of point estimate
How odds is calculated? - ANSWER Number of outcome events
------------------------------÷
Number of non-outcome events
How odds ratio (OR) is calculated? - ANSWER Odds in group 1 (A/B)
-------------------------÷
Odds in group 2 (C/D)
What is odds ratio (OR)? - ANSWER The measure of association calculated from a
case-control study
What does it mean if the risks of two data sets don't overlap? - ANSWER There is a
statistical difference between the two
What is the p-value? - ANSWER The probability that the difference between values
occurred by chance
Measures the strength of the association between exposure and outcome
What does a low p-value mean? - ANSWER The difference is unlikely to have been
produced by chance (significant difference)
What does a high p-value mean? - ANSWER The difference is likely to be due to chance
(not significant difference)
, What cut-off value is used to signify statistical significance? - ANSWER p=0.05
Under what circumstance is OR a good estimate of RR? - ANSWER When disease
prevalence is low
What does a RR > 1mean? - ANSWER A person is likely to be in that group
What does a RR < 1 mean? - ANSWER A person is less likely to be in that group
Explain the differences between risk and odds: - ANSWER Risk:
-More precise of population prevalence
-Easier to understand
-Used to measure association from cohort studies
Odds:
-Easier to calculate
-Use to measure association from case-control studies
What does risk and odds are both measure? -ANSWER The relationship between
exposure and outcome
What RR and OR measure? -ANSWER the difference between two groups
The size of the association between exposure and outcome
What does selective presentation of the data do? -ANSWER Skew/manipulate the
appearance of the data and how its interpreted
What it the interpretation of the data need to be based on? -ANSWER Statistical analysis
Solutions Latest Update
What is risk? - ANSWER Aka prevalence
The possibility of an event to happen
How is the risk measured? - ANSWER Number of outcome events
------------------------------× 100
Number of all events
What is relative risk/ risk ratio (RR)? - ANSWER -The ratio of two risks
-Comparison of the risks of two groups
-The measure of association calculated from a cohort study
-Divide one risk by the other to get an "x times more likely" statement
How is RR measured? - ANSWER Risk in group 1 (A/(A+B))
----------------------------
Risk in group 2 (C/(C+D))
What factors impact how valid a set of calculations are? - ANSWER Sample size
Lack of representation
Lack of random sampling
Bias
What is a point estimate? - ANSWER A single number computed from sample data used
to estimate a population parameter
,95% confidence interval - ANSWER The range within which we are 95% certain that the
true value or the measurement falls
Measures reliability of point estimate
How odds is calculated? - ANSWER Number of outcome events
------------------------------÷
Number of non-outcome events
How odds ratio (OR) is calculated? - ANSWER Odds in group 1 (A/B)
-------------------------÷
Odds in group 2 (C/D)
What is odds ratio (OR)? - ANSWER The measure of association calculated from a
case-control study
What does it mean if the risks of two data sets don't overlap? - ANSWER There is a
statistical difference between the two
What is the p-value? - ANSWER The probability that the difference between values
occurred by chance
Measures the strength of the association between exposure and outcome
What does a low p-value mean? - ANSWER The difference is unlikely to have been
produced by chance (significant difference)
What does a high p-value mean? - ANSWER The difference is likely to be due to chance
(not significant difference)
, What cut-off value is used to signify statistical significance? - ANSWER p=0.05
Under what circumstance is OR a good estimate of RR? - ANSWER When disease
prevalence is low
What does a RR > 1mean? - ANSWER A person is likely to be in that group
What does a RR < 1 mean? - ANSWER A person is less likely to be in that group
Explain the differences between risk and odds: - ANSWER Risk:
-More precise of population prevalence
-Easier to understand
-Used to measure association from cohort studies
Odds:
-Easier to calculate
-Use to measure association from case-control studies
What does risk and odds are both measure? -ANSWER The relationship between
exposure and outcome
What RR and OR measure? -ANSWER the difference between two groups
The size of the association between exposure and outcome
What does selective presentation of the data do? -ANSWER Skew/manipulate the
appearance of the data and how its interpreted
What it the interpretation of the data need to be based on? -ANSWER Statistical analysis
