Question

1) Suppose we are betting on a horse named Epi Beauty, which has a 75% of probability of winning the race. What are the odds that the horse will win the race?

(a) 3.0

(b) 0.75

(c) 0.25

(d) 1.5

Questions refer to the following table.

2) The table summarizing data on the duration of oral contraceptive (OC) use in a case-control study of breast cancer showed the following results

	Breast Cancer
	Cases	Controls	Total
OC use
Ever	273	2641	2914
Never	716	7260	7976
Total	989	9901	10,890

What was the ratio of controls to cases?

(a) 10:1

(b) 1:9

(c) 9:1

(d) 1:1

(e) 1:10

3) (2 POINTS) The association between job-related exposure to welding fumes and chronic obstructive pulmonary disease (COPD) was explored in a case-control study. The following data were reported for 399 COPD patients: 37 currently employed as welders; the remainder had no occupational exposure. Among 800 controls, 48 were employed as welders. Set up a 2 by 2 table and calculate the OR. (Report your answer with one decimal place).

Answer 1

1) Odds that the horse will win the race = Probability of horse winning/Probability of horse losing = 0.75/0.25 = 3

So option a is correct.

2) Total of control = 9901

Total of cases= 989

So the required ratio is 9901:989 or 10:1

So option a is correct.