Hi Safyre, here's some additional info from the STATA help site:
https://www.stata.com/stb/stb59/sbe36_1/diagt.hlp
"^diagt^ displays various summary statistics for a diagnostic test,
compared to patients' true disease status, sensitivity, specificity,
and predictive values, from a 2x2 table. ... #a #b #c #d are, respectively, the numbers of true positives
(diseased subjects with correct positive test results), false negatives
(disease, but negative test), false positives (no disease, but positive
test) and true negatives (no disease, negative test)."
best wishes!
https://www.stata.com/stb/stb59/sbe36_1/diagt.hlp
"^diagt^ displays various summary statistics for a diagnostic test,
compared to patients' true disease status, sensitivity, specificity,
and predictive values, from a 2x2 table. ... #a #b #c #d are, respectively, the numbers of true positives
(diseased subjects with correct positive test results), false negatives
(disease, but negative test), false positives (no disease, but positive
test) and true negatives (no disease, negative test)."
best wishes!