Positive |
True positive (a) |
False positive (b) |
Negative |
False negative (c) |
True negative (d) |
|
The definitions used in the present guideline are as follows: |
|
True positive (TP) |
Those with a positive screening test and confirmed cancer |
(a) |
False positive (FP) |
Those with a positive screening test and no confirmed cancer |
(b) |
True negative (TN) |
Those with a negative screening test and no confirmed cancer |
(d) |
False negative (FN) |
Those with a negative screening test and confirmed cancer |
(c) |
Positive predictive value (PPV) |
Proportion of people with a positive screening test who have confirmed cancer |
(a/[a+b]) |
Sensitivity |
Proportion of people with cancer who have a positive screening test |
(a/[a+c]) |
Specificity |
Proportion of people who do not have cancer who have a negative screening test |
(d/[b+d]) |