Occult blood testing of the stool has a notoriously low sensitivity for picking up cancer (i.e. it has a very high rate of false negatives), and thus in this individual with an increased risk of colorectal cancer based on family history you would not want to use occult blood test for fear of a false negative result (where the test was negative but the individual actually had cancer).
FA2020 p388 lists screening guidelines for colorectal cancer.
In this individual with what would be considered a higher pretest probability, the test would be known to have a higher positive predictive value and a lower negative predictive value. It is not uncertainty surrounding these that would affect the decision (FA2020 p257)
submitted by โcassdawg(1780)
Occult blood testing of the stool has a notoriously low sensitivity for picking up cancer (i.e. it has a very high rate of false negatives), and thus in this individual with an increased risk of colorectal cancer based on family history you would not want to use occult blood test for fear of a false negative result (where the test was negative but the individual actually had cancer).
"It exhibited a sensitivity of 12.9%-79.4% with a specificity of 86.7%-97.7% for CRC screening in many studies."
FA2020 p388 lists screening guidelines for colorectal cancer.
In this individual with what would be considered a higher pretest probability, the test would be known to have a higher positive predictive value and a lower negative predictive value. It is not uncertainty surrounding these that would affect the decision (FA2020 p257)