Exam 1

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Question #1

The broader definition of epidemiology is “the study of the distribution and determinants of health-related states or events in specified populations and…” (choose one best answer),,

A the use of this information to cure medical problems.

B the application of this study to control of health problems.

C the employment of such findings to preventive and curative programs.

D the transfer of this knowledge to preventive programs.

Question #2

If sensitivity and specificity of the test remain unchanged what will happen with PPV and NPV if the prevalence of the disease increases?

A The PPV will increase and NPV will remain unchanged

B The PPV will decrease and NPV will increase

C The PPV will increase and NPV will decrease

D The PPV will remain unchanged and NPV will decrease

E Both PPV and NPV will remain unchanged

Question #3

You are given information about the number of people and the number of deaths in each of the age categories in populations A and B. You also have the standard population and the number of people in each of the age categories in it. What type of adjustment of rates can be performed given information above? (Choose the best answer)

A Indirect adjustment of mortality rates by age and sex

B Neither direct not indirect adjustment of rates

C Direct adjustment of mortality rates by age

D Indirect adjustment of mortality rates by age

E Direct adjustment of mortality rates by age and sex

Question #4

Standardized mortality ratio (SMR) is used to compare mortality rates in two or more populations using indirect adjustment of rates? (Mark as True or False)

A FALSE

B TRUE

Question #5

Intrasubject variability refers to variation in reading test results by different readers. (Mark as True or False)

A TRUE

B FALSE

Question #6

You are given information about the number of people in each of the age categories in populations A and B and the total number of deaths in each population. In addition, you are given the number of people and the number of deaths in each of the age categories in the standard population. What type of adjustment of death rates should be performed given information in the table below? (Choose the best answer)

A Direct adjustment of mortality rates by age and sex

B Indirect adjustment of mortality rates by age and sex

C Direct adjustment of mortality rates by age

D Indirect adjustment of mortality rates by age

Question #7

Kappa Statistic measures… (choose one best answer)

A To what extend does the agreement between the two readings of the same observer exceed the level of agreement that would results from chance alone

B The percentage of patients’ test results that they disagree on

C To what extend does the agreement between the two observers exceed the level of agreement that would results from chance

D The percentage of patients’ test results that they agree on

E To what extend does the disagreement between the two observers exceed the level of agreement that would results from chance

Question #8

Percent agreement between two or more observers is the first step in calculation of kappa statistics and represents observed percent agreement. (Mark as True or False)

A TRUE

B FALSE

Question #9

The screening test in laboratory has 98% sensitivity and 99% specificity. In real world test results could not be replicated. Can this test considered to be reliable? (Circle one best answer)

A Yes

B No

Question #10

Total number of deaths from all causes in a town X with population 300,000 was 260. There were also 240 cases of a disease Q observed. 24 died of a disease Q. Calculate mortality ratio in this population. Use multiplier 10,000. Show calculations for credit.

A 260/300,00=8.6 per 10,000

Question #11

Why the measure of disease occurence calculated above is important (at least one reason)?

A Because it’s used to describe how often the disease occurs in a population.

Question #12

In 1949 one of the most important cohort studies was started, the Framingham study. 5,000 residents were enrolled into the study. At the initial examination 80 of 5,000 were identified as having heart disease. After the initial examination eligible subjects of the Framingham study were followed for 5 years to determine the frequency of the development of heart disease: 220 of these subjects developed heart disease over this time period. Calculate the measure of disease occurence based on your answer on the previous question. Use multiplier 10,000. Show calculations for credit.

A 220/5,000*10,000=440 per 10,000

Question #13

In 1949 one of the most important cohort studies was started, the Framingham study. 5,000 residents were enrolled into the study. At the initial examination 80 of 5,000 were identified as having heart disease. After the initial examination eligible subjects of the Framingham study were followed for 5 years to determine the frequency of the development of heart disease: 220 of these subjects developed heart disease over this time period. Are the 220 cases described above incident or prevalent cases?

A Prevalent

B Incident

Question #14

Why the measure of disease occurence calculated above is important (at least one reason)?

A Because it allows us to see the number of cases of disease present in a specific time.

Question #15

In 1949 one of the most important cohort studies was started, the Framingham study. 5,000 residents were enrolled into the study. At the initial examination 80 of 5,000 were identified as having heart disease. Calculate the measure of disease occurence that can be derived from the presented data based on your answer on the previous question. Use multiplier 1,000. Show calculations for credit.

A 16

Question #16

A Prevalent

B Incident

Question #17

Calculate the case-fatality (CF) rate for Ebola outbreak in Zaire in 2014-2016. Use multiplier 100 (i.e. present the result as a percentage). Show all calculations for credit.

A 2,543/3,811*100= 66.7% CF rate

Question #18

Which one of the food items from the previous question (potato salad, tuna salad or chicken wrap) is more likely responsible for the outbreak of gastroenteritis in this population and why?

A Tuna Salad

Question #19

Calculate the risk of illness (attack rates) among persons who ate each food item, i.e. potato salad, tuna salad and chicken wrap. Use 100 multiplier (i.e. present the result as a percentage). Show calculations for credit.

A Tuna Salad: 135/150*100= 90% attack rate Potato Salad: 130/220*100= 59% attack rate Chicken Wrap: 136/190*100= 71% attack rate

Question #20

A cohort consisted of 1,921,260 individuals, of whom during initial examination 1,887,060 did not have diabetes and 34,200 had type 2 diabetes. Calculate appropriate measure of disease occurence using information described above. Use multiplier 1,000. Show calculations for credit.

A 34,200/1,921,260* 1,000= 17.8 per thousand.

Question #21

A cohort consisted of 1,921,260 individuals, of whom during initial examination 1,887,060 did not have diabetes and 34,200 had type 2 diabetes. What type of measure of disease occurence can be calculated using information described above. (choose one best answer)

A Incidence

B Prevalence

C Risk

D Rate

Question #22

During a foodborne outbreak the illness is transmitted through … (choose one best answer)

A Indirect transmission via common vehicle exposure

B Direct transmission via common vector

C Direct transmission via common vehicle exposure

D Indirect transmission via common vector

Question #23

Disease is a result of interaction between the host, the vector and the environment. (mark as True or False)

A TRUE

B FALSE

Question #24

One way in which sequential and simultaneous testing differ is that… (choose one best answer)

A sequential testing uses two very expensive tests whereas simultaneous testing uses one inexpensive test and one very expensive test.

B simultaneous testing uses one test first then recalls those who test positive for a second test, whereas sequential testing screens the entire population with two tests.

C sequential testing results in gain in the net specificity but loss in the net sensitivity whereas simultaneous testing results in loss in the net specificity but gain in the net sensitivity

D sequential testing results in gain in the net sensitivity and the net specificity whereas simultaneous testing results in loss in the net sensitivity and the net specificity.

Question #25

Which conditions must be met for herd immunity to exist? (choose one best answer)

A single host species, infection induces partial immunity, multiple means of transmission (i.e., indirect and direct).

B multiple animal species and human hosts, infection induces partial immunity, relatively direct transmission.

C single host species, infection induces solid immunity, relatively direct transmission.

D multiple animal species and human hosts, infection induces solid immunity, multiple means of transmission (i.e., indirect and direct).

Question #26

The occurrence of a disease clearly in excess of normal expectancy on several continent or worldwide is referred to as: (choose one best answer)

A Pandemic disease

B Epizootic disease

C Epidemic disease

D Panzootic disease