Table 2.
Sensitivity and diagnostic yield in whole cohort and subgroups
| Valid test | Confirmed tuberculosis by strict reference standard | True positive | Sensitivity | 95% CI | ||
|---|---|---|---|---|---|---|
| Diagnostic test | ||||||
| Whole cohort (n=582) | ||||||
| Alere LAM | 519 (89·2%) | 375 | 171 | 0·46 | 0·40–0·51 | |
| Blood Xpert Ultra | 578 (99·3%) | 423 | 161 | 0·38 | 0·33–0·43 | |
| CD4 count less than 100 cells per μL (n=375) | ||||||
| Alere LAM | 329 (87·7%) | 254 | 145 | 0·57 | 0·51–0·63 | |
| Blood Xpert Ultra | 372 (99·2%) | 288 | 145 | 0·50 | 0·44–0·56 | |
| Haemoglobin less than 8 g/dL (n=207) | ||||||
| Alere LAM | 175 (84·5%) | 144 | 89 | 0·62 | 0·53–0·70 | |
| Blood Xpert Ultra | 206 (99·5%) | 170 | 80 | 0·47 | 0·39–0·55 | |
| Lactate less than 2·5 g/dL (n=142) | ||||||
| Alere LAM | 119 (83·8%) | 97 | 49 | 0·51 | 0·40–0·61 | |
| Blood Xpert Ultra | 139 (97·9%) | 115 | 59 | 0·51 | 0·42–0·61 | |
| Died by week 12 (n=123) | ||||||
| Alere LAM | 101 (82·1%) | 74 | 39 | 0·53 | 0·41–0·64 | |
| Blood Xpert Ultra | 121 (98·4%) | 89 | 49 | 0·55 | 0·44–0·65 | |
| qSOFA score 2 or more (n=124) | ||||||
| Alere LAM | 108 (87·1%) | 77 | 39 | 0·51 | 0·39–0·62 | |
| Blood Xpert Ultra | 124 (100%) | 87 | 44 | 0·51 | 0·40–0·61 | |
| Diagnostic yield | ||||||
| Whole cohort | ||||||
| Sputum Xpert | 582 | 447 | 275 | 0·62 | 0·57–0·66 | |
| Alere LAM | 582 | 447 | 162 | 0·43 | 0·38–0·47 | |
| Tuberculosis blood culture | 582 | 447 | 190 | 0·36 | 0·32–0·41 | |
| Blood Xpert Ultra | 582 | 447 | 165 | 0·37 | 0·32–0·42 | |
| CD4 less than 100 cells per μL | ||||||
| Sputum Xpert | 374 | 300 | 185 | 0·62 | 0·56–0·67 | |
| Alere LAM | 374 | 300 | 152 | 0·51 | 0·45–0·56 | |
| Tuberculosis blood culture | 375 | 301 | 146 | 0·49 | 0·43–0·54 | |
| Blood Xpert Ultra | 374 | 300 | 148 | 0·49 | 0·44–0·55 | |
| Haemoglobin less than 8 g/dL | ||||||
| Sputum Xpert | 205 | 177 | 112 | 0·63 | 0·56–0·70 | |
| Alere LAM | 205 | 177 | 92 | 0·52 | 0·44–0·59 | |
| Tuberculosis blood culture | 207 | 179 | 78 | 0·44 | 0·36–0·51 | |
| Blood Xpert Ultra | 205 | 177 | 82 | 0·46 | 0·39–0·54 | |
| Lactate more than 2·5 g/dL | ||||||
| Sputum Xpert | 140 | 122 | 67 | 0·55 | 0·46–0·64 | |
| Alere LAM | 140 | 122 | 52 | 0·43 | 0·34–0·52 | |
| Tuberculosis blood culture | 142 | 124 | 63 | 0·51 | 0·42–0·60 | |
| Blood Xpert Ultra | 140 | 122 | 60 | 0·49 | 0·4–0·58 | |
| Died by week 12 | ||||||
| Sputum Xpert | 123 | 96 | 53 | 0·55 | 0·45–0·65 | |
| Alere LAM | 123 | 96 | 48 | 0·45 | 0·35–0·55 | |
| Tuberculosis blood culture | 123 | 96 | 43 | 0·50 | 0·40–0·60 | |
| Blood Xpert Ultra | 123 | 9 | 51 | 0·53 | 0·43–0·63 | |
| qSOFA score 2 or more | ||||||
| Sputum Xpert | 124 | 92 | 51 | 0·55 | 0·45–0·66 | |
| Alere LAM | 124 | 92 | 44 | 0·48 | 0·37–0·58 | |
| Blood Xpert Ultra | 124 | 92 | 44 | 0·48 | 0·37–0·58 | |
LAM=lipoarabinomannan. Xpert=Xpert MTB/RIF. Xpert Ultra=Xpert MTB/RIF Ultra. qSOFA=quick sepsis-related organ failure assessment.