Table 3.
Accuracy of the Ellume home influenza test compared with laboratory reference polymerase chain reaction values (N=605).
| Accuracy | True positive, n (%) | False positive, n (%) | False negative, n (%) | True negative, n (%) | Sensitivity (95% CI) | Specificity (95% CI) | PPVa (95% CI) | NPVb (95% CI) | |||||||||
| Overall | |||||||||||||||||
|
|
All | 53 (8.8) | 25 (4.1) | 34 (5.6) | 493 (81.5) | 61 (50-71) | 95 (93-97) | 68 (56-78) | 94 (91-95) | ||||||||
|
|
≤72 hours (n=344) | 32 (9.3) | 17 (4.9) | 19 (5.5) | 276 (80.2) | 63 (48-76) | 94 (91-97) | 65 (50-78) | 94 (90-96) | ||||||||
|
|
>72 hours (n=261) | 21 (8) | 8 (3.1) | 15 (5.7) | 217 (83.1) | 58 (41-74) | 96 (93-98) | 72 (53-87) | 94 (90-96) | ||||||||
| Influenza A | |||||||||||||||||
|
|
All | 42 (6.9) | 3 (0.5) | 28 (4.6) | 532 (87.9) | 60 (48-72) | 99 (98-100) | 93 (82-99) | 95 (93-97) | ||||||||
|
|
≤72 hours (n=344) | 25 (7.3) | 1 (0.3) | 15 (4.4) | 303 (88.1) | 63 (46-77) | 100 (98-100) | 96 (80-100) | 95 (92-97) | ||||||||
|
|
>72 hours (n=261) | 17 (6.5) | 2 (0.8) | 13 (5) | 229 (87.7) | 57 (37-75) | 99 (97-100) | 89 (67-99) | 95 (91-97) | ||||||||
| Influenza B | |||||||||||||||||
|
|
All | 11 (1.8) | 22 (3.6) | 6 (1) | 566 (93.6) | 65 (38-86) | 96 (94-98) | 33 (18-52) | 99 (98-100) | ||||||||
|
|
≤72 hours (n=344) | 7 (2) | 16 (4.7) | 4 (1.2) | 317 (92.2) | 64 (31-89) | 95 (92-97) | 30 (13-53) | 99 (97-100) | ||||||||
|
|
>72 hours (n=261) | 4 (1.5) | 6 (2.3) | 2 (0.8) | 249 (95.4) | 67 (22-96) | 98 (95-99) | 40 (12-74) | 99 (97-100) | ||||||||
aPPV: positive predictive value.
bNPV: negative predictive value.