Name: Yara Langeveld Course: Epidemiology (AM_470707)
Student ID: yla201 Master: MPA
Student number: 2760223 Date: 12/01/2023
BPO assignment 2
Part one: Sensitivity and specificity
Explain the use of the Hepatitis B test for factor VIII screening to lay people. Read the following:
Your role is again that of Don Francis. You have introduced the possibility of using the Hepatitis
B-test to screen factor VIII for the new virus. Jim, however, needs a short draw‐up to convince the
directors of the American Red Cross and America’s Blood Centers to invest in testing factor VIII.
Jim: “I personally don’t care if these people were painted by Norman Rockwell, we still have to prove
the blood is contaminated! We have got to prove it! What do we know? What do we think? What – can
– we – proof?!”
Dale: “It is in factor VIII!”
Jim: “Think?”
Dale: “I know”
Jim: “Prove it!”
Dale: “Well, we can’t prove anything is in the blood, until we have a test.”
Mary: “And we can’t develop a test until we find the virus.”
Harold: “Yes, assuming that it even is a virus.”
(…)
Jim: “Does anybody have anything positive?!”
Don: “Well, we may be able to do something about the blood supply. Even though we can’t find the
virus. We know that the people who are getting this disease are almost identical to the group of people
that are getting Hepatitis B. So, we did an experiment: we took the Hepatitis B-test and took blood
samples from 60 gay‐men who got it, and 60 men who don’t. The test was 88% effective in detecting
the disease.”
Mary: “Really?!”
Harold: “That is fantastic!”
Jim has asked you to write a brief note (150 – 250 words) in which you tabulate the study results
and explain the sensitivity and specificity to lay‐people (i.e. the directors of the blood banks).
Assume a 72% specificity.
Student ID: yla201 Master: MPA
Student number: 2760223 Date: 12/01/2023
BPO assignment 2
Part one: Sensitivity and specificity
Explain the use of the Hepatitis B test for factor VIII screening to lay people. Read the following:
Your role is again that of Don Francis. You have introduced the possibility of using the Hepatitis
B-test to screen factor VIII for the new virus. Jim, however, needs a short draw‐up to convince the
directors of the American Red Cross and America’s Blood Centers to invest in testing factor VIII.
Jim: “I personally don’t care if these people were painted by Norman Rockwell, we still have to prove
the blood is contaminated! We have got to prove it! What do we know? What do we think? What – can
– we – proof?!”
Dale: “It is in factor VIII!”
Jim: “Think?”
Dale: “I know”
Jim: “Prove it!”
Dale: “Well, we can’t prove anything is in the blood, until we have a test.”
Mary: “And we can’t develop a test until we find the virus.”
Harold: “Yes, assuming that it even is a virus.”
(…)
Jim: “Does anybody have anything positive?!”
Don: “Well, we may be able to do something about the blood supply. Even though we can’t find the
virus. We know that the people who are getting this disease are almost identical to the group of people
that are getting Hepatitis B. So, we did an experiment: we took the Hepatitis B-test and took blood
samples from 60 gay‐men who got it, and 60 men who don’t. The test was 88% effective in detecting
the disease.”
Mary: “Really?!”
Harold: “That is fantastic!”
Jim has asked you to write a brief note (150 – 250 words) in which you tabulate the study results
and explain the sensitivity and specificity to lay‐people (i.e. the directors of the blood banks).
Assume a 72% specificity.
