3.      Several studies have found that approximately 92% of cases of lung cancer are due to cigarette smoking. This measure is an example of: [ONE POINT]

a. An incidence rate
b. A relative risk

c. A prevalence risk
d. An attributable risk

e. A proportionate mortality ratio

4.      Researchers select 100 patients with colon cancer and 300 patients without colon cancer. Of the 100 patients with colon cancer, 15 smoke cigars while 40 of the 300 patients without colon cancer smoke cigars.

a.       Calculate a measure of association between colon cancer and cigar smoking. Show your work. [ONE POINT]

b. Interpret the measure of association you calculated. [ONE POINT]

5.      Complete the Table 1 (Table below) by calculating the polio incidence rates, disease-specific mortality rates, and case-fatality for each of the past five years.  Interpret the data and the trend over time. [THREE POINTS]

Table 1. Incidence, mortality and case fatality.

Questions 6 and 7 refer to the following information:

The results of a 10-year cohort study of smoking and coronary heart disease (CHD) are shown above:

6.      The incidence of CHD in smokers that can be attributed to smoking is: [ONE POINT]

7.      The proportion of the total incidence of CHD in smokers that is attributable to smoking is: [ONE POINT]  

Cases

Controls

Ever

99

959

Never

80

683

Total

179

1642

CASES

CONTROLS

SMOKERS

1322

1282

NON SMOKERS

35

75

TOTAL

1357

1357

1357

1357

Table 4. results of a retrospective cohort study

Food

Ate

Did not  eat

Ill

well

total

AR

Ill

well

total

AR

RR

Meat

14

20

34

35

30

65

Spinach

31

10

41

10

22

32

Potato

10

43

53

10

30

40

Salad

15

11

26

28

19

47

Ice cream

20

10

30

6

16

22

$20,000

54(45.8%)

22(51.2%)

$21-$40,000

40(33.9%)

11(25.6%)

$41-$60,000

13(11%)

5(11.6%)

$61-$80,000

7(5.9%)

3(7%)

>$80,000

4(3.3%)

2(4.6%)

Employmentstatus*

Employed

38(31.7%)

25(56.8%)

Unemployed

63(52.5%)

13(29.5)

Retired

19(15.8%)

6(13.6%)

32.  Correlation coefficients describe the direction and magnitude of a linear relationship between how many variables? [ONE POINT]

A) 1

B) 4

C) 3

D) 2

34.  The nurse researcher is calculating the standard deviation. What is the standard deviation? [ONE POINT]

a)      The average amount of deviation of values from the mode and is calculated for every other score

b)      The average amount of deviation of values from the median and is calculated for every other score

c)      The average amouUse the space assigned after each question for your answer. All the questions must be answered, justified and show your calculations for full credit.

Please write your answers and save the file with your LAST NAME and send as Microsoft word document.

Hand written and pdf files are not accepted.

Total points=60 (30% of the course grade)

1.      Which of the following is a case-control study? [ONE POINT]

a. Study of past mortality or morbidity trends to permit estimates of the occurrence of disease in the future

b. Analysis of previous research in different places and under different circumstances to permit the establishment of hypotheses based on cumulative knowledge of all known factors
c. Study of the incidence of cancer in men who have quit smoking

d. Obtaining histories and other information from a group of known cases and from a comparison group to determine the relative frequency of a characteristic or exposure under study
e. Both a and c

2.      A random sample of middle age sedentary males was selected from four census tracts, and each man was examined for coronary artery disease. All those having the disease were excluded from the study. All others were randomly assigned to either an exercise group, which followed for a two-year program of systematic exercise, or to a control group, which had no exercise program. Both groups were observed semiannually for any difference in incidence of coronary heart disease.

• What type of study (study design) you would assign to this information? Why? [ONE POINT] 

8.      What type of study design is considered to be the ‘gold standard’ in assessing causality? [ONE POINT]

a.  Cohort

b.  Case-control

c.  Ecological

d.  Experimental

9.      In a study of a disease in which all cases that developed were ascertained, if the relative risk for the association between a factor and the disease is equal to 1.0, then: [ONE POINT]

1. The factor protects against development of the disease
2. Either matching or randomization has been unsuccessful
3. There is no association between the factor and the disease
4. The comparison group used was unsuitable, and a valid comparison is not possible
5. There is either no association or a negative association between the factor and the disease

10.  To study the relationship between oral contraceptive use and ovarian cancer, CDC initiated a study – the Cancer and Steroid Hormone Study. Case-patients were enrolled through eight regional cancer registries participating in the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute.

1. What type of study design is this study? [ONE POINT]

2. What types of bias are of particular concern in this study? [ONE POINT]

3. What steps might you take to minimize these potential biases? [ONE POINT]

4. The primary purpose of this study was to measure and test the association between OC use and Ovarian cancer. The distribution of exposure to OCs among cases and controls is shown in Table 2 below.

Table 2. Ever-use of oral contraceptives among ovarian cancer cases and controls,

5. From these data, can you calculate the risk of ovarian cancer among oral contraceptive

users? Why or why not? [ONE POINT]

6. What is confounding? Under what circumstances would age be a confounder in this

study? [TWO POINTS]

11.  What is effect modification? How do you look for it? Give example [TWO POINTS]

12.  All of the following are important criteria when making causal inferences except: [ONE POINT]

1. Consistency with existing knowledge
2. Dose-response relationship
3. Consistency of association in several studies
4. Predictive value
5. Strength of association
   
   
   

13.  Which of the following is not an advantage of a prospective cohort study? [ONE POINT]

a. Precise measurement of exposure is possible
b. Incidence rates can be calculated

d. Recall bias is minimized compared with a case-control study

c. It usually costs less than a case-control study
e. Many disease outcomes can be studied simultaneously

14.  A major problem resulting from the lack of randomization in a cohort study is: [ONE POINT]

a. The possibility that a greater proportion of people in the study may have been exposed
b. The possibility that a smaller proportion of people in the study may have been exposed

c. The possibility that a factor that led to the exposure, rather than the exposure itself, might have caused the disease
d. That, without randomization, the study may take longer to carry out
e. Planned crossover is more likely

15.  Which of the following is an approach to handling confounding? [TWO POINTS]

a.       Individual matching

b.      Stratification

c.       Group matching

d.      Adjustment

e.       All of the above

16.  Residents of three villages with three different types of water supply were asked to participate in a survey to identify cholera carriers. Because several cholera deaths had occurred recently, virtually everyone present at the time underwent examination. The proportion of residents in each village who were carriers was computed and compared. What is the proper classification for this study? [ONE POINT]

a. Case-control study
b. Concurrent cohort study

c. Cross-sectional study
d. Non-concurrent cohort study

      e. Experimental study

Question 17 is based on the information given below:

In a case-control study of the relationship of radiation exposure and thyroid cancer, 50 cases admitted for thyroid cancer and 100 “controls” admitted during the same period for treatment of hernias were studied.  Only the cases were interviewed, and 20 of the cases were found to have been exposed to x-ray therapy in the past, based on the interviews and medical records.  The controls were not interviewed, but a review of their hospital records when they were admitted for hernia surgery revealed that only 2 controls had been exposed to x-ray therapy in the past.

17.  Based on the description given above, what source of bias is least likely to be present in this study? [ONE POINT]

1. Recall bias
2. Bias due to controls being non-representative of the non-diseased population
3. Bias due to use of different methods of ascertainment of exposure in the cases and controls
4. Bias due to loss of subjects from the control group over time
5. Selection bias for exposure to x-ray therapy in the past
   
   
   

18.  When a new treatment is developed that prevents death but does not produce recovery from disease, the following will occur:  (ONE POINT)

a. Prevalence of the disease will decrease

b. Incidence of the disease will increase

c. Prevalence of the disease will increase

d. Incidence of the disease will decrease

e. The incidence and the prevalence of the disease will decrease

19.  Data for the case-control study were obtained from hospitalized patients in London and vicinity over a 4-year period (April 1948 – February 1952). Initially, 20 hospitals, and later more, were asked to notify the investigators of all patients admitted with a new diagnosis of lung cancer. These patients were then interviewed concerning smoking habits, as were controls selected from patients with other disorders (primarily non-malignant) who were hospitalized in the same hospitals at the same time.

The following table (table 3) shows the relationship between cigarette smoking and lung cancer among male cases and controls.

Table 3. Smoking status, lung cancer cases and matched controls with other diseases.

1. How representative of all persons with lung cancer are hospitalized patients with lung

cancer? [ONE POINT]

2. How representative of the general population without lung cancer are hospitalized

patients without lung cancer? [ONE POINT]

3. Estimate the odds ratio from the data in table 3 (ABOVE) and interpret the odds ratio. [TWO POINTS]

20.  During July 2014, a county health department received reports of 26 new cases of measles.

What additional information is needed to determine whether this group of cases is an outbreak? [ONE POINT]

21.  Data on 1075 male respondents to the 2003 Health Information National Trends

Study were collected from October 2002 to April 2003 and analyzed in 2008 to examine the associations among race/ethnicity, and the perception of the risk of developing prostate cancer for African-American, Hispanic, and non-Hispanic white men aged ≥45 years without a history of prostate cancer.

- What study design is been used for this study? Why? [ONE POINT]

22.  Explain the relationship between specificity and false positive results? Give example (ONE POINT)

23.  Under what circumstances would it be desirable to minimize the percentage of individuals with false negative results on a test?  (ONE POINT)

24.  In a study of a disease in which all cases that developed were ascertained, if the relative risk for the association between a factor and the disease is more than 1.0, then: [ONE POINT]

1. The factor protects against development of the disease
2. Either matching or randomization has been unsuccessful
3. The comparison group used was unsuitable, and a valid comparison is not possible
4. There is an association between the factor and the disease and the factor is a risk factor
5. There is either no association or a negative association between the factor and the disease

25.  Fill in the spaces: [THREE POINTS]

The mean (X ) is a measure of ________________ __________________ of a distribution while the SD is a measure of _____________________ of its scores.  Both X and SD are_________________ statistics.

26.  The following list represents the number of nursing students enrolled in a particular nursing program between the years of 2001 and 2007, respectively:

525, 567,610, 525, 579, 649, and 699.

Calculate the mean, median, and mode of the number of the nursing students enrolled in the above program between 2001 and 2007. Show your calculations. [THREE POINTS]

MEAN =

MEDIAN =

MODE =

27.  The figure below represented the number of cases of salmonella isolation by months of isolation. 

a.       Examine the figure below and indicate if there is an outbreak or not? [ONE POINT]

b.      If yes, discuss the steps for conducting an outbreak investigation for this disease. [TWO POINTS]

28.  The figures (1, 2, and 3) below represented the epidemiologic curve for outbreak investigation. Discuss the type of source of the epidemic for each figure (THREE POINTS).

29.  The following table represents the results of a study to investigate an outbreak of gastroenteritis in California.  Using the data in table 4 (the table below), complete the following:

a.       Attack rate (AR) for those who ate the specific identified food and those who did not eat these food [ONE POINT]

b.      The relative risk (RR) for each specific identified food [ONE POINT]

c.       Which food is the most likely cause of the outbreak? Why? [ONE POINT]

d.      What steps you will take after the identification of the source of outbreak?  [ONE POINT]

30.  What demographic variable(s) were measured at the nominal level of measurement in table 5? Provide a rationale for your answer. [TWO POINTS]

Table5.Frequency Counts and Percentages on Demographic Data (N=120)

Descriptive Variable                      Total Sample n(%)                      Depressed (n=44)

Age(year)

29-38                                                3(2.5%)                               0

39-48                                              16(13.3%)                           8(18.2%)

49-58                                              35(29.2%)                         13(29.5%)

59-68                                              37(30.8%)                         10(22.7%)

=>69                                      29(24.2%)                        13(9.5%)

Gender

Male                                                45(37.5%)                      17(38.6%)

Female                                            75(62.5%)                      27(61.4%)

Ethnicity

Hispanic                                  97(80.8%)                      36(81.8%) African American                           22(18.3%)                        7(15.9%) Asian                                                1(.8%)                            1(2.3%)

Maritalstatus*

Single                                                7(6)                                 0(0%)

Married                                           80(67%)                           32(73%)

Divorced                                               11(9%)                                 4(9%)

Widowed                                         22(18%)                              8(18%)

Socioeconomicstatus

Note. *Significant at P<0.05.

31.  Which ethnic group in table 5 had the most individuals who are depressed?[ONE POINT]

33.  Consider r = 0.96 and r = –0.96. Which r value is stronger? Provide a rationale for

your answer?[TWO POINTS]

 nt of deviation of values from the mean and is calculated for every score

d)      The average amount of deviation of values from the median and is     calculated for every score