Deck 3: The Occurrence of Disease: Idisease Surveillance and Measures of Morbidity

Question 1

Suppose that the incidence of all types of cancer remains constant in a given country.However,thanks to new treatments,the survival of cancer patients increases.What do you expect to happen to the prevalence of cancer in that country?

A) Increase
B) Decrease
C) Remain constant
D) Cannot be determined
E) Duplicate

Answer 1

A
When the duration (survival) of a disease increases and the incidence remains constant,the prevalence will increase (remember that prevalence = incidence × duration).

Question 2

Which of the following statements is the most accurate definition?

A) Active surveillance often gathers disease data from all potential reporting health care providers.
B) Passive surveillance provides stimulus to health care providers in the form of individual feedback or other incentives.
C) Sentinel surveillance is a type of surveillance based on selected population samples chosen to represent the relevant experience of particular groups.
D) Active surveillance is continuous analysis, interpretation, and feedback of systematically collected data, generally using methods distinguished by their practicality, uniformity, and rapidity rather than by accuracy or completeness.
E) Passive surveillance is an observational investigation, usually descriptive, in which information is systematically collected.

Answer 2

C
Sentinel surveillance is a type of surveillance system.Instead of attempting to gather surveillance data from all health care providers,a sentinel surveillance system selects,either randomly or intentionally,a small group of healthproviders from whom to gather data."Active surveillance often gathers disease data from all potential reporting health care providers" is not correct.Active surveillance stimulus to health care providers in the form of individual feedback or other incentives.In active surveillance,providers contacted on regular basis to collect information.It is more resource intensive and mostly used for outbreak investigations or pilot studies."Passive surveillance provides stimulus to health care providers in the form of individual feedback or other incentives" is not correct.Passive surveillance gathers disease data from all potential reporting health care providers.It is the most common type of surveillance.Providers are responsible for reporting."Active surveillance is continuous analysis,interpretation,and feedback of systematically collected data,generally using methods distinguished by their practicality,uniformity,and rapidity rather than by accuracy or completeness" is not correct.This is one of the general definitions of surveillance.Surveillance is also defined a systematic and continuous collection,analysis,and interpretation of data,closely integrated with the timely and coherent dissemination of the results and assessment to those who have the right to know so that action can be taken."Passive surveillance is an observational investigation,usually descriptive,in which information is systematically collected" is not correct.A survey is an observational investigation,usually descriptive,in which information is systematically collected.

Question 3

At an initial examination in Baltimore,Maryland,disease X was found in 10 of 1,000 men aged 40 to 50 years and in 10 of 2,000 women aged 30 to 40 years.Which of the following statement is the most accurate inference for the risk of developing disease X?

A) Men have a 2 times greater risk of developing disease X than women.
B) Women have a 2 times greater risk of developing disease X than men.
C) People aged between 40 and 50 years have a 2 times greater burden of developing disease X than people aged between 30 and 40.
D) People aged between 30 and 40 years have a 2 times greater burden of developing disease X than people aged between 40 and 50.
E) We cannot make any inference of risk of developing disease X.

Answer 3

E
The information provided in question is only prevalence of disease X at an initial examination.Based on information from prevalence,we cannot make any inference for risk of developing disease X.We should have newly diagnosed cases in a certain amount of time with population at risk for risk calculation and comparison."Men have a 2 times greater risk of developing disease X than women," "Women have a 2 times greater risk of developing disease X than men," "People aged between 40 and 50 years have a 2 times greater burden of developing disease X than people aged between 30 and 40," and "People aged between 30 and 40 years have a 2 times greater burden of developing disease X than people aged between 40 and 50" are not correct.Because we cannot perform a risk comparison based on disease prevalence.The accurate statement on disease prevalence is "Men aged 40 to 50 years have 2 times of greater prevalence of disease X than women aged 30 to 40 years."

Question 4

An epidemiologist decides to investigate the incidence of diabetes in a population of 300 older adults who live in a nursing home.She visits the nursing home in January 1,2017 and later in December 31 of the same year.She looks into the records of these patients and learns that in her first visit,25 patients had diabetes and 35 in her second visit.What number should be in the numerator for her calculation of incidence?

A) 10
B) 25
C) 35
D) 300
E) 275

Question 5

In the student's health clinic of a certain university,140 cases of foot-hand-mouth disease were identified among the undergraduate students.This viral infection is usually mild,and none of the students got any complication.Because it is rare to observe this condition in people older than 10 years,the university reported their findings to the city's health department.Three officers were sent to the university to interview and examine all the infected students and their contacts.By sending the three officers,what type of surveillance was implemented by the city health department in response to the university's report?

A) Sentinel
B) Periodic
C) Systematic
D) Passive
E) Active

Question 6

An epidemiologist decides to investigate the incidence of diabetes in a population of 300 older adults who live in a nursing home.She visits the nursing home in January 1,2017 and later in December 31 of the same year.She looks into the records of these patients and learns that in her first visit,25 patients had diabetes and 35 in her second visit.What number should be included in the denominator for her calculation of incidence?

A) 10
B) 25
C) 35
D) 300
E) 275

Question 7

What is the incidence rate from influenza in 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) 3,000 cases
B) 150 cases/1,000 people
C) 1,000 cases
D) 100 cases/1,000 people
E) 15 cases/1,000 people