Table 4 Relative and absolute incremental yields and NND for smear and cultures
From: High yield of culture-based diagnosis in a TB-endemic setting
Relative incremental yield vs. | ||||
|---|---|---|---|---|
Yield | 1st S | 2 S total | 1st C | |
Expected # of P after 1 S = 377/2537 = 14.9% | ||||
Expected # of P after 2 S = 508/2537 = 20.0% | 1.3 | |||
Expected # of P after 1 C = 682/2537 = 26.9% | 1.8 | 1.3 | ||
Expected # of P after 2 C = 760/2537 = 29.9% | 2.0 | 1.5 | 1.1 | |
Absolute incremental yield vs. | ||||
Yield | 1st S | 2 S total | 1st C | |
Expected # of P after 1 S = 377/2537 = 14.9% | ||||
Expected # of P after 2 S = 508/2537 = 20.0% | 5.2% | |||
Expected # of P after 1 C = 682/2537 = 26.9% | 12.0% | 6.9% | ||
Expected # of P after 2 C = 760/2537 = 29.9% | 15.1% | 9.9% | 3.1% | |
NND vs. | ||||
NND | 1st S | 2 S total | 1st C | |
1st Smear | 7 | |||
2 Smears total | 5 | 19 | ||
1st Culture | 4 | 8 | 15 | |
2 Cultures total | 3 | 7 | 10 | 33 |