Deck 4: The Occurrence of Disease: II. Mortality and Other Measures of Disease Impact

Question 1

According to the Centers of Disease Control and Prevention (CDC),during the Ebola outbreak of 2014 in West Africa,there were a total of 14,124 Ebola cases in Sierra Leone and 3,956 deaths due to Ebola.What was the case fatality rate in that country?

A) 3.5%
B) 22%
C) 28%
D) 3,956
E) 14,124

Answer 1

C
3,956 deaths represent 28% of the total number of cases of Ebola.This proportion is known as the case-fatality rate.

Question 2

A researcher finds that the standardized mortality rate (SMR) for epidemiologists compared with the general population is 100.What does that mean?

A) The observed number of deaths for epidemiologists is the same as the expected.
B) Epidemiologists have a mortality rate 100 times greater than the general population.
C) Epidemiologists have a mortality rate 100 times lower than the general population.
D) The general population experience a mortality rate increased as compared with epidemiologists.
E) Nothing can be said with this information.

Answer 2

A
SMR = 100 indicates that the observed number of deaths is the same as the expected.

Question 3

What is the attack rate (case-fatality rate) from influenza during the 2016 season in the young age group at Minas Tirith? Use the following table to answer the question. Number of Residents,Diagnosed Cases,and Deaths From Influenza by Age

A) 15%
B) 5%
C) 1.5%
D) 10%
E) 50%

Answer 3

D
Attack rate equals number of deaths divided by number of diagnosed cases.There are 300 deaths and 3,000 diagnosed cases in the young age group.The attack rate is 0.1 (10%),which is 300 divided by 3,000.15% is not correct; 15% is the incidence rate from influenza in the young age group.However,percentage is a unit of incidence rate.5% is not correct; 5% is the mortality rate from influenza in the old age group.However,percentage is a unit of mortality rate.1.5% is not correct; 1.5% is the mortality rate from influenza in the young age group.However,percentage is a unit of mortality rate.50% is not correct; 50% is the attack rate from influenza in the old age group.

Question 4

What is the mortality from influenza during the 2016 season in the old age group at Minas Tirith? Use the following table to answer the question. Number of Residents,Diagnosed Cases,and Deaths From Influenza by Age

A) 300 deaths
B) 500 deaths
C) 150 deaths/1,000 people
D) 100 deaths/1,000 people
E) 50 deaths/1,000 people

Question 5

In 2016 there were 7,467 million people in the world.According to the World Health Organization,in the same year there were 56.9 million deaths worldwide; of those,15.2 million were due to ischemic heart disease or stroke.What was the proportionate mortality of those two causes combined for that year?

A) 0.8%
B) 0.2%
C) 3.7%
D) 13.5%
E) 26.7 %

Question 6

Calculate the age-adjusted death rate from disease X in cities A and B by the direct method,using the total of both cities as the standard population.What is the age-adjusted death rate from disease X for City B? Use the following table to answer the question. Number of Residents and Deaths From Disease X by Age Group in City A and City B

A) 53 deaths/1,000 people
B) 32 deaths/1,000 people
C) 10 deaths/1,000 people
D) 75 deaths/1,000 people
E) 43 deaths/1,000 people

Question 7

For a disease such as seasonal influenza,which is less fatal and of short duration?

A) Incidence rates and mortality rates will be similar.
B) Mortality rates will be much higher than incidence rates.
C) Incidence rates will be much higher than mortality rates.
D) Incidence rates will be unrelated to mortality rates.
E) None of the above.

Question 8

What is the age-specific mortality rate from disease X in City B for age younger than 65? Use the following table to answer the question. Number of Residents and Deaths From Disease X by Age Group in City A and City B

A) 53 deaths/1,000 people
B) 32 deaths/1,000 people
C) 10 deaths/1,000 people
D) 75 deaths/1,000 people
E) 43 deaths/1,000 people

Question 9

What is the crude death rate from disease X for City A? Use the following table to answer the question. Number of Residents and Deaths From Disease X by Age Group in City A and City B

A) 53 deaths/1,000 people
B) 32 deaths/1,000 people
C) 10 deaths/1,000 people
D) 75 deaths/1,000 people
E) 43 deaths/1,000 people

Question 10

City A suffered some political changes and was divided into two cities named Alpha and Beta.Five years after the division,mortality rates in both cities are compared.The all-cause mortality rate in City Alpha is much higher than the rate in Beta.When looking at the demographic characteristics in the cities,you notice that the age distribution is almost exactly the same in both cities.What do you expect to find when the age-adjusted mortality rates are calculated and compared?

A) City Alpha will have a much higher age-adjusted mortality rate than Beta.
B) City Beta will have a much higher age-adjusted mortality rate than Alpha.
C) The age-adjusted mortality rate will be much lower than the unadjusted rate in Alpha.
D) The age-adjusted mortality rate will be much lower than the unadjusted rate in Beta.
E) The answer cannot be determined without the actual numbers.

Question 11

The mayor of Baby City is interested in comparing the infant mortality rate (infants are defined as babies younger than the age of 12 months) of Baby City with the infant mortality rate of Adult City.He argues that the age distributions of these cities are very different and therefore asks you to calculate the age-adjusted infant mortality rate.What is the best approach?

A) Use direct adjustment.
B) Use indirect adjustment.
C) Calculate the standardized mortality ratio.
D) Explain that no age adjustment is needed when comparing with age-specific mortality rates.
E) Use the World Health Organization standard population to calculate an adjusted rate.

Question 12

Which of the following statements is the most accurate interpretation of disease occurrence in City A and City B? Use the following table to answer the question. Number of Residents and Deaths From Disease X by Age Group in City A and City B

A) The age-adjusted mortality rate of City A is still higher than the mortality rate of City B, as compared with the crude mortality rate.
B) The age-adjusted mortality rates for City A should be used to make decisions regarding allocation of funding for hospital care of the dying in City A.
C) For direct age-adjustment, the weight for a given age category is the percentage of deaths for that age group.
D) For direct age-adjustment, the weight for a given age category is the number of individuals in the standard population for that age group.
E) The difference in the adjusted mortality rates between City A and City B is always attributable to differences in age composition between the two populations.