Table 2.
Sensitivity, specificity, predictive value of a positive result, and efficiency for pregnancy diagnosis with real time ultrasonography between 17 and 24 d postmating compared with farrowing results.
| Days postmating
|
||||
|---|---|---|---|---|
| 17 to 18 ( n = 35) | 19 to 20 (n = 46) | 21 to 22 (n = 43) | 23 to 24 (n = 18) | |
| Correctly diagnosed pregnant | 19 | 24 | 28 | 14 |
| Incorrectly diagnosed pregnant | 8 | 13 | 7 | 2 |
| Correctly diagnosed open | 4 | 4 | 2 | 1 |
| Incorrectly diagnosed open | 4 | 5 | 6 | 1 |
| Sensitivity (%) | 82.6 | 85.7 | 93.3 | 93.7 |
| Specificity (%) | 33.3 | 27.8 | 46.1 | 33.3 |
| PPR+ (%) | 70.3 | 64.8 | 80.0 | 88.2 |
| Efficiency (%) | 65.7 | 60.8 | 69.7 | 83.3 |
PPR+ — predictive value of a positive result