An important characteristic of glaucoma, an eye disease, is the presence of classical visual field loss. Tonometry is a common form of glaucoma screening, whereas, for example, an eye is classified as positive if it has an intraocular pressure of 21 mmHg or higher at a single reading. Given the data shown in Table E1.28, calculate the sensitivity and specificity of this screening test.
| Field Loss |
Test Result |
Total |
|
Positive |
Negative |
|
| Yes |
13 |
7 |
20 |
| No |
413 |
4567 |
4980 |