Tools of Population Based Health

Question 1

What is a significant shortcoming of epidemiologic studies?

Answer 1

Very small observed increases in disease rates for exposed compared with unexposed groups are likely to be accounted for by bias, confounding, or chance occurrence.

Question 2

What is NOT an advantage of the cohort study?

Answer 2

The cohort study provides a fuller picture of the health effects of the study factor because of the ability to look at more than one disease.

Question 3

What reflects a cross-sectional study design?

Answer 3

Americans have a high prevalence of heart disease. They also eat a high-fat diet.

Question 4

What is the significance of having “1” in the confidence interval?

Answer 4

It means that the p value must have been set at 0.05.

Question 5

What is an example of confounding factor?

Answer 5

A case-control study of a blue-collar occupation and bladder cancer fails to take account of cigarette smoking.

Question 6

What does NOT represent evidence of cigarette smoking causing lung cancer?

Answer 6

The longest study of cigarette smoking was 50 years in duration.

Question 7

What is bias and confounding?

Answer 7

Bias: systematic error related to study design or execution
Confounding: distortion by an extraneous variable that is somehow related to exposure and outcome

Question 8

Importance of central limit theorem?

Answer 8

States that no matter what the shape of the parent population distribution, the sampling distribution of a statistic (say a “sampling mean”) will have a normal distribution

Question 9

What does the 2x2 table calculate for cohort and case-control studies? (Biostatistics)

Answer 9

Cohort: Relative risk (link to population)

Case-Control: Odds ratio

Question 10

Difference between experimental and observational studies?

Answer 10

Experimental studies: evidence from double-blind randomized controlled trials
Observational studies: “natural experiments” (unplanned)