Intro to epidemiology - Master of Public Health Flashcards
Which is false? Environmental factors include... A. Cultural traits B. Genetics C. Psychological influences D. Behaviours
B. Genetics are NOT an environmental factor.
Which is the correct organisation of an epidemic curve?
A. Time on the y-axis and no. of cases on the x-axis
B. No. Of cases on the y-axis and date on the x-axis
C. Age on the y-axis and mortality rate on the x-axis
B. An epidemic curve has no. of cases on the y-axis and date on the x-axis, describing the prevalence of the disease over time.
How do new treatments affect the incidence and prevalence of a disease?
A. They will not affect the incidence unless an infectious disease that is cured more quickly with the treatment, meaning the disease will have less chance to be spread to new hosts.
B. Prevalence will increase if the treatment allows cases to live longer with the disease.
C. Prevalence will decrease if the treatment cures cases quickly.
D. All of the above.
D.
Which of these characteristics will cause a disease to have a high prevalence?
A. It is common
B. It has a short duration
C. It is rare
D. It is chronic
A and D. Chronic conditions have a higher prevalence as people are sick for a long time and the more common the disease, the higher it’s prevalence at any one time.
Which measure of disease does this statement describe?
“Percentage of population living with a particular health condition at one time”
A. Incidence
B. Prevalence
C. Attack rate
B.
Which of these statements describe the use of spot maps?
A. Show the spread of disease
B. Inform hypotheses of points of origin and modes of transmission
C. Depict the geographic distribution of cases
D. All of the above
D.
In what cases is P approximately equal to IR X D? A. High prevalence of disease B. Rare disease C. Stationary population D. High death rate and low birth rate
B and C. For a less rare disease, P/1 - P is approx. equal to IR X D
When is using the person-time method particularly useful?
A. When the cohort is composed of subjects of different ages
B. When new cases are difficult to diagnose
C. When people are studied for different lengths of time.
C.
Person-time is a measure of the number of people studied x the total time each was studied for.
What is the denominator when calculating point prevalence?
A. No. of people in population
B. New cases of disease
C. Total no. of people with disease
A.
Point prevalence = no. Of people with disease / no. Of people in population
Which of these does period prevalence take into account?
A. Prevalence of disease at the beginning of a period
B. New cases of disease during the period
Both A & B.
Which of these descriptions relates to cumulative incidence/incidence proportion?
A. Proportion of a population with the disease at one time
B. Proportion of population at risk that actually develop disease within a specified period
C. Rate of new cases appearing in the whole population
B.
This is also the probability or average risk that an individual will develop the disease during a certain time interval.
E.g. if 30% developed the disease, there is a 30% chance of developing the disease.
Which type of study has minimum loss to follow up?
A. Prospective cohort study
B. Case-control study
C. Clinical trial
C.
Clinical trials have a clearly defined study group and minimum loss to follow up. This means incidence proportion in clinical trials is more appropriate.
Which is true?
People are at risk of developing the disease until…
A. They are lost to follow up or develop the disease
B. They die from the disease
C. They recover from the disease
A.
In a study with a total of 44.5 person-years and 4 people who develop the disease, what is the incidence rate?
A. 11 cases per person-year
B. 11 cases per 100 person-years
C. 9 cases per 100 person-years
C.
4/44.5 = 0.09 cases per person-year = 9 cases per 100 person-years
