Study Designs: Ecologic, Complete Test Bank + Chapter 6

Chapter: Chapter 06 - Quiz

True/False

1. A case-control study is purely a descriptive (as opposed to analytic) study design.

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2. An ecologic study is one that examines a group as a unit of analysis.

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3. An ecologic comparison study is sometimes called a cross-sectional ecologic study.

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4. A cross-sectional study allows measurement of the temporal ordering of cause and effect.

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5. In a case-control study, cases and controls are compared in order to determine whether they differ with respect to their exposure levels.

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Multiple Choice

1. Which of the following is an example of exposure data in ecologic studies?

A) Per capita income

B) Mean ambient temperatures

C) Smoking prevalence

D) Per capita calorie intake

E) All are correct.

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2. Case-control studies are among the best observational designs to study diseases of:

A) high prevalence.

B) high validity.

C) low case fatality.

D) low prevalence.

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3. Examples of descriptive epidemiologic studies do not usually include:

A) cohort studies.

B) counts.

C) case series.

D) cross-sectional studies.

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Questions 4–13:

A large medical center’s oncology program reported an increased number of cases of pancreatic cancer during a certain month. The hospital’s epidemiologist decided to research the problem. Tumor registry records were searched to identify all cases of pancreatic cancer during a five-year period; cancer patients were matched with patients treated for other diseases during the same five-year period. All subjects in the study were questioned about lifestyle factors including alcohol, tea, and coffee consumption. The resulting data are as follows:

Note: Total number of male cancer patients = 200

Total number of female cancer patients = 150

Total number of male patients (other diseases) = 300

Total number of female patients (other diseases) = 300

4. What type of study is this?

A) Experimental

B) Case-control

C) Intervention

D) Clinical trial

E) Cohort

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5. Does this study have an exposure status variable?

A) No

B) Yes, lifestyle

C) Yes, disease type

D) Yes, sex of patient

E) Insufficient information to answer this question

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6. Does this study have a disease status variable?

A) No

B) Yes, lifestyle

C) Yes, cancer

D) Yes, sex of patient

E) Insufficient information to answer the question

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7. Which of the following best approximates risk associated with alcohol drinking in men?

A) 2.11

B) 0.92

C) 0.71

D) 0.62

E) 1.37

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8. Which of the following best approximates risk associated with alcohol drinking in women?

A) 0.21

B) 1.37

C) 2.11

D) 0.62

E) 0.92

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9. Which of the following best approximates risk associated with tea drinking in men?

A) 3.50

B) 1.37

C) 0.71

D) 2.51

E) 0.92

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10. Which of the following best approximates risk associated with tea drinking in women?

A) 0.92

B) 1.37

C) 3.50

D) 0.71

E) 3.50

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11. Which of the following best approximates risk associated with coffee drinking in men?

A) 0.63

B) 2.11

C) 0.94

D) 1.02

E) 3.50

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12. Which of the following best approximates risk associated with coffee drinking in women?

A) 2.11

B) 0.94

C) 3.50

D) 0.63

E) 1.02

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13. Which factor has the strongest association with cancer for both men and women?

A) Alcohol consumption

B) Tea drinking

C) Coffee drinking

D) The factors show no variation in the association.

E) Not enough information to determine

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14. In case-control studies, the odds ratio is used as an estimate of the relative risk. In order for this approximation to be reasonable, some conditions must be met. Which of the following conditions is not necessary in order to use the odds ratio to estimate the relative risk?

A) With respect to exposure, controls are representative of the population to which you want to generalize your results.

B) The event (disease) under study is rare in the population.

C) The exposure in question is rare in the population.

D) Cases are representative of all cases.

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15. Which of the following is true of ecologic studies?

A) They are expensive and require a great deal of time to conduct.

B) They may be affected by the ecologic fallacy.

C) They provide accurate measurements of exposure.

D) They yield results that can be applied directly to individuals.

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Essay

1. An epidemiologist found five cases of big toe cancer in the Yukon Territory. Because there were only a few cases, the epidemiologist decided to conduct a matched case-control study to determine whether shoe size larger than 9 is a risk factor for big toe cancer. Each case was individually matched to one control for daily activity, history of athlete’s foot, and history of ingrown toenails. The following data were gathered:

Shoe size > 9

Compute the proper measure of association. Interpret your results.

Classroom Activity

1. One way to help students appreciate differences among the types of observational study designs is to work through some examples in class. The examples might include various methods of sample selection, measures of exposure, measures of disease frequency, and measures of association that can be estimated from each design. A good approach is to create slides with the following:

• An ecologic study (refer to Figure 6-5, p. 247)
• A cross-sectional study (refer to Figure 6-10, p. 254)
• A case-control study (refer to Figure 6-16, p. 262)

For each of these study designs, make up some numbers to fill in a two-by-two table. Work through (together or after students have had a chance to try on their own) each of the measures of frequency and association that have been introduced in the chapter. This activity can be supplemented with exercises on study designs contained in the Student Study Guide.