Question

Help me please someone!!

The tests done to determine if someone is HIV positive are called Enzyme immunoassay or EIA tests. The test screens a blood sample for the presence of antibodies to HIV. Like most tests, this test is not perfect. The table below shows the approximate probabilities of positive and negative EIA tests when the blood does and does not actually contain the HIV antibodies. Long range studies have shown that only 2% of the population actually has the HIV antibodies.

a) Explain in context all four values in the table. That is, what does each of them actually mean?

Answer 1

To the best of my knowledge, this is what I gather the table's values mean:

"antibodies present" and "positive" give you the percent of people who had the antibodies and the tests showed they did (hence, positive).

"antibodies present" and "negative" give you the percent of people who did have the antibodies, yet the tests read otherwise (misdiagnosed, negative when it should be positive).

"antibodies not present" and "positive" also show a percentage of people who were misdiagnosed. these people did not have the antibodies yet they tested positive for them.

"antibodies not present" and "negative" show the percent of people who did not have the antibodies and who were tested to prove just that.