Table 2.
Performance of RISK11, symptom screening, and the LAM assay as triage or diagnostic tests for tuberculosis at baseline
| RISK11 (60)*(n=820) | Symptom screening (n=861) | LAM lateral flow assay (n=858) | ||
|---|---|---|---|---|
| Not tested or inadequate sample | 41† | 0 | 3‡ | |
| Positive test | 285 (35%) | 51 (6%)§ | 14 (2%)¶ | |
| Primary endpoint (two or more positive samples) | ||||
| Risk ratio (95% CI; p value) | 13·1 (2·1–81·6; p=0·0016) | 6·8 (1·9–23·1; p=0·0012) | 6·7 (1·1–34·5; p=0·036) | |
| AUC | 88·2% (77·6–96·7) | NA | NA | |
| Sensitivity | 87·5% (58·3–100·0) | 30·0% (0·0–62·5) | 10·0% (0·0–33·3) | |
| Specificity | 65·8% (62·5–69·0) | 94·4% (92·8–95·9) | 98·5% (97·6–99·3) | |
| Positive predictive value‖ | 2·5% (0·7–4·4) | 5·9% (0·0–13·2) | 7·1% (0·0–25·0) | |
| Negative predictive value‖ | 99·8% (99·4–100·0) | 99·1% (98·4–99·8) | 98·9% (98·2–99·5) | |
| Secondary endpoint (one or more positive samples) | ||||
| Risk ratio (95% CI; p value) | 5·6 (1·9–16·4; p=0·0006) | 3·2 (1·0–9·6; p=0·051) | 3·5 (0·6–17·1; p=0·18) | |
| AUC | 80·3% (71·4–88·2) | NA | NA | |
| Sensitivity | 75·0% (50·0–94·4) | 16·7% (0·0–36·4) | 5·6% (0·0–18·8) | |
| Specificity | 66·0% (62·7–69·2) | 94·3% (92·8–95·8) | 98·5% (97·6–99·3) | |
| Positive predictive value‖ | 4·2% (2·0–6·7) | 5·9% (0·0–13·2) | 7·1% (0·0–25·0) | |
| Negative predictive value‖ | 99·3% (98·5–99·8) | 98·1% (97·2–99·0) | 98·0% (97·0–98·9) | |
Data are n (%) or % (95% CI), unless otherwise specified. AUC=area under the receiver operating characteristic curve. LAM=lipoarabinomannan. NA=not applicable.
A priori (60%) RISK11 score threshold.
Four participants did not have PAXgene RNA samples available and 37 had an indeterminate RISK11 result, probably because of inadequate quality of the RNA sample, and were excluded from the analysis. Two of these participants had prevalent primary endpoint tuberculosis and one had incident primary endpoint tuberculosis.
All three participants missing LAM assay results did not have tuberculosis at baseline.
Includes two participants with prevalent primary endpoint tuberculosis who were excluded from RISK11 analysis because of missing results.
Includes one participant with prevalent primary endpoint tuberculosis who was excluded from RISK11 analysis because of missing results.
Computed by use of prevalence in the study population.