TABLE 3.
Sensitivities, specificities, and positive and negative predictive values for Cobas Amplicor MTB and smear compared with culture results from one to three sputum specimens collected within a week from each patienta
| No. of specimens (sample size) | Cobas Amplicor MTB
|
Smear
|
||||||
|---|---|---|---|---|---|---|---|---|
| Sensitivity (%) | Specificity (%) | Positive predictive value (%) | Negative predictive value (%) | Sensitivity (%) | Specificity (%) | Positive predictive value (%) | Negative predictive value (%) | |
| One specimen (n = 151) | 82 (60–95) | 98 (89–100) | 95 (74–100) | 92 (81–97) | 59 (36–79) | 98 (89–100) | 93 (66–100) | 84 (71–92) |
| Two specimens (n = 99) | 82 (60–95) | 98 (89–100) | 95 (74–100) | 92 (81–97) | 59 (36–79) | 98 (89–100) | 93 (66–100) | 84 (71–92) |
| Three specimens (n = 69) | 91 (71–99) | 98 (89–100) | 95 (76–100) | 96 (86–99) | 64 (41–83) | 98 (89–100) | 93 (68–100) | 85 (73–93) |
a
The 95% confidence intervals are in parentheses.