Mcq_sem3_mini1 - Epidemiology - Quiz, Flashcards & Trivia

1. Validity can be defined as:

The degree to which an instrument measures what it is supposed to measure.

The degree to which results are consistent on a repeat measurement

A measure of the degree or strength of association between two variables

Concerned with measuring the frequency of new cases with reliability

None of the above

2. Reliability can be defined as:

The degree to which an instrument measures what it is supposed to measure.

The degree to which results are consistent

A measure of the degree or strength of association between two variables.

Concerned with measuring the frequency of new cases with reliability

Ensuring that patients all take a test under the same conditions.

3. You would typically use a descriptive study

For a comparison between a new SSR1 drug and Venlafaxine

To document a cluster of Wegener's granulomatosis cases that has recently appeared in your area

To evaluate the effects of Team Based Learning (TBL) versus didactic lecture

None of the above

4. In 1945 there were 1,000 women who worked in a factory painting radium dials on watches. The incidence of bone cancer in these women up to 1975 was compared with that of 1,000 women who worked as telephone operators in 1975. Twenty of the radium dial painters and four of the telephone operators developed bone cancer between 1945 and 1975. This study is an example of a

Experimental study

Case series

Clinical trial

Cohort study

Case-control study

5. Reliability can be defined as:

The degree to which an instrument measures what it is supposed to measure

The degree to which results are consistent

A measure of the degree or strength of assoclation between two variables

Concerned with measuring the frequency of new cases with reliability

Ensuring that patients all take a test under the same conditions

6. An outbreak of gastritis occurred on a cruise ship. The data in the following table were obtained shortly after the outbreak, from a questionnaire completed by everyone on board the ship. What is the relative risk of developing gastritis from herring consumption?

0,5

2,0

2.3

8,0

1,0

7. Question 2-3. The following table gives the results of a screening test for diabetes compared to a confirmatory evaluation (oral glucose tolerance test).

The sensitivity of this screening test for diagnosing diabetes is:

23%

29%

63%

99%

100%

8. Regionville is a community of 100,000 persons. During 1985 there were 1,000 deaths from all causes. All cases of tuberculosis have been found and they total 300 - 200 males and 100 females. During 1985, there were 60 deaths from tuberculosis, 50 of them males. The crude mortality rate for Regionville is

300 per 100,000

60 per 1,000

10 per 1,000

100 per 1,000

200 per 1,000

9. A comparison of clinically diagnosed versus autopsy-confirmed gastric and peptic ulcers was performed or 100„000 consecutive diseased patients in several large hospitals as shown in the following table,

From these data, the sensitivity of clinical diagnosis was:

1,500/1700

200/96,000

95,800/96,000

1,500/4,000

2,500/4,000

10. Epidemic refers to

A disease that has a low rate of occurrence but that is constantly present in a community or region

An attack rate in excess of 10 per 1,000 population

The occurrence of finesses of similar nature clearly in excess of the normal expectation for that population at that time

Diseases of the respiratory system that occur seasonally

The annual case rate per 100,000 population

11. An outbreak of gastritis occurred on the Northern Star cruise ship travelling from New York to Nassau. The data in the table below was obtained from a questionnaire completed by everyone on board the ship, shortly after the outbreak. Data from an Outbreak of Gastritis on the Northern Star Cruise Shuzii FOOD People who ate food People who did not eat food

	Sick	Well	Sick	Well
Shrimp and rice	200	SOO	100	900
Chicken	650	350	100	900
Stir fried pork	200	800	500	500
Oysters	300	700	400	600
Chocolate mousse	600	400	450	550

Given this information, what is the relative risk of developing gastritis from Shrimp and rice on the Northern Star ship?

5.0

1.0

3.2

2,0

7.5

12. You would typically use a descriptive study

For a comparison between a new SSRI drug and Venlafaxine

To document a cluster of Wegener's granulomatosis cases that has recently appeared in your area

To evaluate the effects of Team Based Learning (TBL) versus didactic lecture

None of the above

13. Validity can be defined as:

The degree to which an instrument measures what it is supposed to measure.

The degree to which results are consistent on a repeat measurement

A measure of the degree or strength of association between two variables.

Concerned with measuring the frequency of new cases with reliability

None of the above

14. In a study of 500 cases of a disease and 500 controls, the suspected etiological factor is found in 400 cases and 100 controls. The absolute risk of disease in people with the factor is

. 80%

40%

16%

20%

Cannot be computed from the data given

15. A school district has been using an intelligence test to evaluate students and make important placement decisions, such as who gets placed into gifted and other special education settings. However, a group of psychologists advises the school district that there is a problem with this particular test. More specifically, the criticism is that scores on this test correlate too highly with students socioeconomic status. This criticism most directly suggests a problem with the test's:

Internal consistency

Test-retest reliability

Discriminant validity

Convergent validity

Predictive validity

16. The mean birth weight of first-born infants of 23 women who smoked more than one pack of cigarettes per day during pregnancy was 200 g lower than those of the first-born infants of 16 women who never smoked, The difference was statistically significant at the 5% level (P<0,05). This means which of the following?

Smoking during pregnancy retards fetal growth

The difference observed between mean birth weights was too large to have occurred by chance alone

The difference observed between mean birth weights could have been easily occurred by chance alone

The number of patients studied was not sufficient to achieve a conclusive result

Smoking during pregnancy does not influence fetal growth

17. The followingfigure showthe epidemiccurveforanoutbreak offeverandrashamonga group of children at a summer camp. They were exposed to a younger relative of one of the campers with fever and rash who had come to visit on the 9^{th •} ^{The average incubation period for the organism in this outbreak is}

8 days

12 days

16 days

20 days

18. California Highway Patrol statistics revealed that more accidents occurred to blue cars than to cars of any other color. The inference that while driving a blue car, one is at higher risk of an accident than while driving a car of another color is

Correct

Incorrect, because the comparison is not based on rates

Incorrect, because no control or comparison group is used

Incorrect, because no test of statistical significance has been made

Incorrect, because prevalence is used instead of incidence

19. Question 2-3. The following table gives the results of a screening test for diabetes compared to a confirmatory evaluation (oral glucose tolerance test).

The specificity of this screening test for diagnosing diabetes is

23%

29%

63%

99%

100%