A comparison of the T-SPOT.TB and QFT-GIT assays where both tests were undertaken
| QFT-GIT | ||||
| Positive | Negative | Indeterminate | Total | |
| T-SPOT.TB positive | 31 | 6 | 0 | 37 (8.1%)* |
| T-SPOT.TB negative | 9 | 289 | 62 | 360 (78%) |
| T-SPOT.TB inconclusive | 3+2 | 43+6 | 8+0 | 62 (14%)‡ |
| Total | 45 | 344 | 70 | n=459 |
| (9.8%)* | (75%) | (15%)† | ||
Comparisons are based on the McNemar test for paired proportions.
A T-SPOT.TB result was inconclusive if the test was not completed or the result was indeterminate.
↵* Proportions positive: 9% (of completed T-SPOT.TB) and 8% (of attempted T-SPOT.TB) vs 10% (QFT-GIT), p=0.3 and p=0.1, respectively.
↵† x+y: T-SPOT.TB number not completed+number indeterminate;
↵‡ Proportions indeterminate: 2% (T-SPOT.TB) vs 15% (QFT-GIT), p<0.0001. Proportions inconclusive (not completed or indeterminate): 14% (T-SPOT.TB) vs 15% (QFT-GIT), p=0.5.