Table 4. Performance characteristics and efficiency of 8-sample and 4-sample pooled testing, by testing platform (n = 302), for detection of severe acute respiratory syndrome coronavirus 2 in prospectively pooled specimens*.
| Testing platform | Pool size | PPA, % (95% CI) | NPA, % (95% CI) | Pools positive, % | Average test run/sample |
|---|---|---|---|---|---|
| LDT | 8 | 71.7 (56.5–84.0) | 98.4 (91.5–100.0) | 30.9 | 0.434 |
| Panther Fusion | 8 | 76.1 (61.2–87.4) | 98.4 (91.5–100.0) | 32.7 | 0.452 |
| Panther Aptima-M | 8 | 73.9 (58.9–85.7) | 100.0 (94.3–100.0) | 30.9 | 0.434 |
| Panther Aptima-350 | 8 | 82.6 (68.6–92.2) | 98.4 (91.5–100.0) | 34.5 | 0.470 |
| LDT | 4 | 94.3 (80.8–99.3)† | 100 (97.7–100.0) | 17.2 | 0.422 |
| Panther Fusion‡ | 4 | 100.0 (85.8–100.0) | 100 (96.7–100.0) | 17.6 | 0.426 |
| Panther Aptima-M | 4 | 82.9 (66.2–93.4)† | 100 (97.7–100.0) | 15.1 | 0.401 |
| Panther Aptima-350 | 4 | 88.6 (73.3–96.8)† | 100 (97.7–100.0) | 16.2 | 0.411 |
*Panther Aptima-M, Panther Aptima with manufacturer-set RLU cutoff value. Panther Aptima-350, Panther Aptima with RLU cutoff value >350 was considered positive. Both products from Hologic (https://www.hologic.com). LDT, laboratory-developed test; NPA, negative percent agreement; PPA, positive percent agreement; RLU, relative light unit.
†Restricting the performance characteristics comparison to only the 136 pools tested by Panther Fusion resulted in a PPA as follows: LDT 100% (95% CI 85.8%–100.0%), Aptima-M 91.7% (95% CI 73.0%–99.0%), and Aptima-350 95.8% (95% CI 78.9%–99.9%).
‡A total of 56 of the 192 pools tested on the other platforms were not tested by Panther Fusion.