Reference no: EM131036195

1. A study is conducted in order to determine the relationship between estrogen therapy and heart attack. The data are summarized below.

	Developed Heart Attack	Did not Develop Heart Attack
Estrogen	305	4,695
No estrogen	75	4,925

Compute the cumulative incidence of heart attack in women who do take estrogen? Round to three decimal places.

2. A study is run to estimate the incidence of atrial fibrillation (AF) in men and women over the age of 60. People with atrial fibrillation and appropriate controls were enrolled and surveyed regarding gender. The data are summarized below.

	Developed AF	Did not Develop AF	Total
Men	120	6453	6573
Women	86	7074	7160

Compute the OR for men compared to women? Record your answer with two decimal places.

3. Suppose you are given the following data for a series of 11 patients and their fasting glucose levels.

3.9          4.2          5.7          4.7          4.5          5.1          3.5          5.3          4.9          6.9          4.1

Calculate the sample mean. Record your answer with two decimal places.

4. In a study of 380 diabetics and nondiabetics, patients were classified as underweight, normal weight, overweight and obese according to their diabetes status. The probability of being normal weight is 0.31 and the probability of having diabetes is 0.39. If you select two individuals from the population, the probability of being diabetic and normal weight is 0.09.

What is the probability that either of the two randomly selected individuals (or both) will be diabetic or normal weight?

a. Pr (diabetic II normal weight)=0.09

b. Pr (diabetic U normal weight)=0.61

c. Pr (diabetic I normal weight)=0.29

d. It is not possible to calculate with the given information

5. A study is planned to assess the effectiveness of a new combination drug for treating nephrolithiasis (kidney stone). One hundred patients with nephrolithiasis will be randomly assigned to receive either the new combination drug or the standard surgical intervention. The efficacy of the new drug will be measured by the time it takes a patient to return to normal activities, measured in days. Identify the appropriate research design for this study.

a. Prospective cohort study

b. Randomized controlled trial

c. Case control study

d. Retrospective cohort study

6. A research study was conducted to assess whether there is an association between stress disorders in pregnancy and autism spectrum disorders (ASD) in their children born out of these pregnancies. Forty children with ASD and fifty without ASD were selected for investigation. Mothers were asked about whether they suffered from stress disorders during their pregnancy. This study is an example of a:

a. Prospective cohort study

b. Retrospective cohort study

c. Case control study

d. Randomized controlled trial

7. In a study of 380 diabetics and nondiabetics, patients were classified as underweight, normal weight, overweight and obese according to their diabetes status. The probability of being normal weight is 0.31 and the probability of having diabetes is 0.39. The probability of being both diabetic and normal weight is 0.09. Comparing the unconditional probability of having diabetes to the conditional probability of diabetes given weight would you say weight and diabetes are independent or not?

a. Weight and diabetes are independent

b. Weight and diabetes are not independent

 8. A study is conducted to investigate the use of a technique called radionuclide venticulography as a test for detecting coronary artery disease. The results are tabulated below.

Screening Test	CAD	No CAD
Positive	302	80
Negative	179	372

What is the sensitivity of the screening test? Please record your answer as a decimal, not a percent and round to two decimal places.

9. Among females in the United States between 18 and 74 years of age, diastolic blood pressure is normally distributed with a mean of 77 mm Hg and standard deviation of 11.6 mm Hg. What is the probability that a randomly selected woman has a diastolic blood pressure less than 60 mm Hg?

a. 0.07

b. +1.47

c. -1.47

d. None are correct

10. A clinical trial is held to compare a newly discovered antihypertensive drug to an existing medication. The study involves a total of 200 hypertension patients. Patients are enrolled and randomized to receive either the experimental new drug or the existing medication. The data shown below are data collected of their systolic blood pressure readings measured at the end of the study after 6 months on the assigned treatments. (Sp = 17.23)

11.         

	New drug (n=100)	Existing drug (n=100)
Mean systolic blood pressure	120.2	131.4

Test if there is a significant difference in mean systolic blood pressures between groups using a=0.05.

a. We reject Ho

b. We accept Ho

c. We do not reject Ho

d. Insufficient information

12. What statistical test would be appropriate to use when assessing the relationship between different cultures (i.e., Italian, Indian, German, American, and Mexican) and the spice levels in their food?

a. Mann-Whitney U

b. T-test

c. ANOVA (Analysis of Variance)

d. Chi-square test of independence

13. Confounding is said to be present in a study where the crude measurement of odds ratio is 2.0, and the adjusted measure is 1.85.

a. True

b. False

c. Insufficient information