Quiz 9 STUDY QUESTIONS
1 For each of the following statements, indicate whether thestatistical association is likely the result of chance,confounding. bias. or A case-control study showed that a strongassociation exists between birth order and Down syndrome.
b. A case-control study lound a positive association betweenself-reported chest radiographs during pregnancy and breast cancer.A randomized clinical trial found that drug A versus placebo didnot significantly improve 10-year survival (RR = 0.35; 95%confidence interval, 01455014 A cohort study found no statisticalassociation between smoking and pancreatic cancer (RR = 1: = Pvalue = 0.85). A hospital-based case-control study identified astrong association between oral contraceptives and thromboembolism.Many doctors suspected the association and hospitalized some womenwho used oral contraceptives for evaluation
2 Match the following methods for minimizing chance, bias, andconfounding in an experimental study Chance Bias Confounding aRandomization b. Blind c. Increase sample size
3. Recall the causal criteria presented by Sir Austin Brad- fordHill in 1965 Discuss these criteria in the context of smoking andlung cancer.
4.Suppose you suspect based on descriptive epidemiol ogy thatcollege students who perform better aca demically are more likelyto have an office job and be obese 10 years after graduation. Youdecide to select 500 graduating seniors randomly and classify themaccording to grade point average as high versus low (where the cutpoint is at the median of the GPAs for these students). Theresulting 2 x 2 contingency table is as follows: Below is a tableGPA High Low Total Obese at 10 Years Yes 60 40 100 No 190 210 400Total 250 250 500 Apply this data to the six steps ofhypothesis.
5. Match the following Predisposing factors Enabling factorsPrecipitating factors Reinforcing factors a Facilitatemanifestation of a disease le housing) Associated with definitiveonset of disease (eg. toxin Increase level of susceptibility m ahost of age) d. Aggravate presence of disease leg repeatedexposure)
6. Compare a direct causal association with an individual causalassociation. Use specific examples
7. Define and compare the difference between static inferenceand causal inference. 8. Why might studying a sample be preferredpopulation? A component cause is also called which of thefollowing?
a. Risk factor b. Web of causation c. Epidemiologic triangle
d. Each of the above are component causes 10 Webs of causationplay a more useful role when one is trying to describe diseaseetiology for which type of disease? a. Acute b. Infectious C.Chronic d. Two of the above.
