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OSUJI GRACE NUR 627: Advanced Epidemiology and Biostatistics for Nursing “Practi

ID: 3202030 • Letter: O

Question

OSUJI GRACE

NUR 627: Advanced Epidemiology and Biostatistics for Nursing

“Practice Questions I”

Due: 2/6/2017

Please save the file with your last name before you attach to Black Board.

The test includes 34 questions for a total of 35 points. (15% of the course grade)

“Please answer all the questions, show your calculations and justify your answer for each question using your own words to get full credit”.

Questions 1 and 2 use the information below:

Population of the city of Atlantis on March 30, 2003 = 183,000

No. of new active cases of TB occurring between January 1 and June 30, 2003 = 50

No. of active TB cases according to the city register on June 30, 2003 = 251

The incidence rate of active cases of TB for the 6-month period was: [ONE POINT]

a.   7 per 100,000 population                50/(183,00- 251) = 2.7 X 100,00

b.   14 per 100,000 population

c.   27 per 100,000 population

d.   28 per 100,000 population

e.   130 per 100,000 population

Rational;= To calculate:

= Number of new cases in a population over a given time period

Number of people at risk during that time period

= 50 new cases of TB

Population of 183,000 during the 6-month period

= 27 per 100,000

The prevalence of active TB as of June 30, 2003, was: [ONE POINT]

a.   14 per 100,000 population                   (251/183,000 ) X 100,000

b.   137 per 100,000 population

c.   144 per 100,000 population

d.   264 per 100,000 population

e.   none of the above

Rationale: To calculate prevalence:

= Number of cases in a population

Population at the time of enumeration

= 251 cases of TB

Population of 183,000 during the 6-month period

137per 100,000 population

Which of the following is an advantage of active surveillance? [ONE POINT]

a.   requires less project staff

b.   is relatively inexpensive to employ

c.   relies on different disease definitions to account for all cases

d.   more accurate due to reduced reporting burden for health care providers

e.   reporting systems can be developed quickly.

Rational; Treatment is given unless the test are positive for a disease, so active surveillance is more benefical

Questions 4 is based on the information given below:

In an Asian country with a population of 10 million people, 80,000 deaths occurred during the year ending December 31, 2005. These deaths included 60,000 deaths from cholera in 90,000 people who were sick with cholera.

What was the case-fatality rate from cholera in 2005? [ONE POINT]

80 death/10 million people = 0.008 or 8 death per.

Rational; . And Rational: The cause-specific mortality rate is calculated as: =

The number of deaths from a specific cause

The number of persons in the population

30,000 deaths

10,000 people

= 0.008, or 8 deaths per 1,000 people

What would be the effect on age-specific incidence rates if women with hysterectomies were included in the denominator of calculations, assuming that there are some women in each age group who have had hysterectomies? [ONE POINT]

a.   the rates would remain the same

b.   the rates would tend to decrease

c.   the rates would tend to increase

d.   the rates would increase in older groups and decrease in younger groups

e.   it cannot be determined whether the rates would increase or decrease

Question 6 is based on the following information:

A colon cancer screening study is being conducted in Nottingham, England. Individuals 50 to 75 years old will be screened with the Hemoccult test. In this test, a stool sample is tested for the presence of blood.

If the Hemoccult test result is negative, no further testing is done. If the Hemoccult test result is positive, the individual will have a second stool sample tested with the Hemoccult II test. If this second sample also tests positive for blood, the individual will be referred for more extensive evaluation. What is the effect on net sensitivity and net specificity of this method of screening? [ONE POINT]

a.   Net sensitivity and net specificity are both increased

b.   Net sensitivity is decreased and net specificity is increased

c.   Net sensitivity remains the same and net specificity is increased

d.   Net sensitivity is increased and net specificity is decreased

e.   The effect on net sensitivity and net specificity cannot be determined from the data

At an initial examination in Oxford, Mass., migraine headache was found in 5 of 1,000 men aged 30 to 35 years and in 10 of 1,000 women aged 30 to 35 years. The inference that women have a two times greater risk of developing migraine headache than do men in this age group is: [ONE POINT]

a.   incorrect, because a ratio has been used to compare male and female rates

b.   incorrect, because of failure to recognize the effect of age in the two groups

c.   incorrect, because no data for a comparison or control group are given

d.   incorrect, because of failure to distinguish between incidence and prevalence

e. correct

Age-adjusted death rates are used to: [ONE POINT]

a.   Determine the actual number of deaths that occurred in specific age groups in a population

b.   Correct death rates for missing age information

c.   Compare deaths in persons of the same age group

d.   Eliminate the effects of differences in the age distributions of populations in comparing death rates

e. Correct death rates for errors in the statement of age

The mortality rate from disease X in city A is 75/100,000 in persons 65 to 69 years old. The mortality rate from the same disease in city B is 150/100,000 in persons 65 to 69 years old. The inference that disease X is two times more prevalent in persons 65 to 69 years old in city B than it is in persons 65 to 69 years old in city A is: [ONE POINT]

a.   Correct

b.   Incorrect, because of failure to adjust for differences in age distributions

c.   Incorrect, because of failure to distinguish between period and point prevalence

d.   Incorrect, because a proportion is used when a rate is required to support the inference

e. Incorrect, because of failure to distinguish between prevalence and mortality

For a disease such as pancreatic cancer, which is highly fatal and of short duration: [ONE POINT]

a.   Mortality rates will be much higher than incidence rates

b.   Incidence rates will be much higher than mortality rates

c.   Incidence rates and mortality rates will be similar

d.   Incidence rates will be unrelated to mortality rates

e.   None of the above

In 1990, there were 7,000 deaths due to lung diseases in miners aged 20 to 64 years. The expected number of deaths in this occupational group, based on age-specific death rates from lung diseases in all males aged 20 to 64 years, was 3,500 during 1990.

What was the standardized mortality ratio (SMR) for lung diseases in miners? [ONE POINT]

Interpret the value of the SMR: [ONE POINT]

Question 12-20 is based on the following information:

A physical examination and an audiometric test were given to 500 persons with suspected hearing problems, of whom 300 were actually found to have them. The results of the examinations were as follows:

PHYSICAL EXAMINATION

HEARING PROBLEMS

Result           Present            Absent

Positive        260                  30

Negative       40                    170

AUDIOMETRIC TEST

HEARING PROBLEMS

Result           Present            Absent

Positive        290                  10

Negative       10                    190

The sensitivity of the physical examination was: [ONE POINT]

The specificity of the physical examination was: [ONE POINT]

The positive predictive value of the physical examination was: [ONE POINT]

The negative predictive value of the physical examination was: [ONE POINT]

The sensitivity of the audiometric test was: [ONE POINT]

The specificity of the audiometric test was: [ONE POINT]

The positive predictive value of the audiometric test was: [ONE POINT]

The negative predictive value of the audiometric test was: [ONE POINT]

Compared with the physical examination, the audiometric test is: [ONE POINT]

a.   Equally sensitive and specific

b.   Less sensitive and less specific

c.   Less sensitive and more specific

d.   More sensitive and less specific

e.   More sensitive and more specific

Which of the following is a good index of the severity of a short-term, acute disease? [ONE POINT]

a.   Cause-specific death rate

b.   5-year survival

c.   Standardized mortality ratio

d. Case-fatality rate

e.   None of the above

The occurrence in a community or region of cases of an illness, specific health-related behavior, or other health-related events clearly in excess of normal expectancy is a/an: [ONE POINT]

Epidemic

B. Pandemic

Endemic

The nurse researcher knows that there are two primary criteria for assessment of an instrument. What is reliability? [ONE POINT]

A)

Degree of consistency or accuracy with which an instrument measures an attribute

B)

Magnitude and direction of a relationship between two variables

C)

Extent to which an instrument yields the same results on repeated administrations

D)

Extent to which an instrument's items are measuring the same attribute

The level of prevention that takes place during the early phases of pathogenesis and includes activities that limit the progression of disease is: [ONE POINT]

Primary Prevention

B. Secondary Prevention

C. Tertiary Prevention

The probability that an event will occur, e.g., that an individual will become ill or die within a stated period of time or by a certain age is: [ONE POINT]

Epidemiologic Transition

B. Risk

C. Hypothesis

A measure that refers to the mortality rate associated with a specific cause of death divided by the population size at the midpoint of a time period times a multiplier is the: [ONE POINT]

Sex-specific Rate

B. Crude Death Rate

Cause-Specific Mortality Rate

The use of vaccines is an example of which level of prevention? [ONE POINT]

Primary prevention

Secondary prevention

Tertiary prevention

Community prevention

Wearing a safety belt is an example of which level of prevention? [ONE POINT]

Primary prevention

Secondary prevention

Tertiary prevention

Community prevention

Providing education to a diabetic on how to use his/her insulin is an example of which level of prevention? [ONE POINT]

Primary prevention

Secondary prevention

Tertiary prevention

Community prevention

Encouraging individuals to take a daily dose of aspirin to reduce the chance of a heart attack is an example of which level of prevention? [ONE POINT]

Primary prevention

Secondary prevention

Tertiary prevention

Community prevention

Which of the following is a measure of disease prognosis? [ONE POINT]

Prevalence

Median survival time

Age-adjusted mortality rates

Standardized mortality ratio

Providing training or instructing patients on how to modify their diets and take their medications to prevent a second heart attack is an example of ________ prevention. [ONE POINT]

primary

secondary

tertiary

community

3

Sensitivity and specificity are important criteria for screening and diagnostic instruments. What is specificity? [ONE POINT]

A)

Different method of measuring the same attributes yielding similar results

B)

Ability to differentiate the construct being measured from other similar concepts

C)

Instrument's ability to identify a case correctly

D)

Instrument's ability to identify non-cases correctly.

Which of the following improves the reliability of diabetes screening tests? [ONE POINT]

Having the same lab analyze all samples

Taking more than one sample for each subject and averaging the results

Insuring that the instrument is standardized before each sample is analyzed

a and c only

All of the above

The nurse researcher knows that there are two primary criteria for assessment of an instrument. What is reliability? [ONE POINT]

A)

Degree of consistency or accuracy with which an instrument measures an attribute

B)

Magnitude and direction of a relationship between two variables

C)

Extent to which an instrument yields the same results on repeated administrations

D)

Extent to which an instrument's items are measuring the same attribute

Explanation / Answer

Specificity (also called the true negative rate) measures the proportion of negatives that are correctly identified as such (e.g., the percentage of healthy people who are correctly identified as not having the condition).

Sensitivity therefore quantifies the avoiding of false negatives, and specificity does the same for false positives.

3. option D is right.

Providing training or instructing patients on how to modify their diets and take their medications to prevent a second heart attack is an example of ___tertiary_____ prevention.

Encouraging individuals to take a daily dose of aspirin to reduce the chance of a heart attack is an example of which level of prevention - primary

A person who was just diagnosed with a disease would be interested in the prognosis of the disease.

Prognosis is predicting the progress or outcome of the disease

Expressing Prognosis : Case-fatality (rate) or CFR, Five-year survival , Observed survival rate , Median survival time, Relative survival rate.

Median survival time is right

reliability : the degree to which the result of a measurement, calculation, or specification can be depended on to be accurate.

The nurse researcher knows that there are two primary criteria for assessment of an instrument. What is reliability : option A is right