Table 1.
Tuberculosis Molecular Bacterial Load Assay and Time to Positivity Over Time
| Classification | Treatment Week | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 14 | |
| Classification by MGIT TTP vs by TB-MBLA (cured, n = 132; relapse, n = 4) | |||||||||||||
| ȃMissing MGIT | 21 | 27 | 29 | 36 | 42 | 47 | 54 | 44 | 60 | 60 | 57 | 61 | 73 |
| ȃMissing MBLA | 13 | 17 | 10 | 13 | 14 | 13 | 10 | 14 | 17 | 20 | 12 | 20 | 28 |
| ȃCured–relapse: pairwise P value for MGIT TTP | .195 | .384 | .071 | .403 | .612 | .031 | .099 | .028 | .016 | .096 | .013 | .246 | .065 |
| ȃCured–relapse: pairwise P value for MBLA | .461 | .016 | .016 | .231 | .095 | .010 | .004 | .003 | .017 | .002 | .203 | .090 | .110 |
| Classification of cured vs relapse: no. correctly identified of No. observed: (fitted line using the coefficients of the linear mixed-effect model for log[TTP] or log[MBL+1]) | |||||||||||||
| ȃBoundary classification (log[TTP]) | 1.918 | 2.098 | 2.264 | 2.417 | 2.557 | 2.684 | 2.798 | 2.899 | 2.987 | 3.062 | 3.123 | 3.172 | 3.230 |
| ȃCorrectly identified cured (log[TTP]) | 82/113 (73%) |
77/105 (73%) |
73/104 (70%) |
64/96 (67%) |
63/91 (72%) |
62/86 (72%) |
58/80 (73%) |
67/88 (76%) |
58/73 (79%) |
54/72 (75%) |
60/76 (79%) |
58/72 (81%) |
58/60 (97%) |
| ȃCorrectly identified relapse (log[TTP]) | 1/2 | 1/4 | 2/3 | 2/4 | 2/3 | 2/3 | 1/2 | 2/4 | 2/3 | 3/4 | 3/3 | 1/3 | 1/3 |
| ȃBoundary classification (log[MBL+1]) | 1.625 | 1.504 | 1.391 | 1.287 | 1.192 | 1.106 | 1.029 | 0.961 | 0.901 | 0.851 | 0.809 | 0.777 | 0.738 |
| ȃCorrectly identified: cured (log[MBL+1]) | 58/120 (48%) | 57/115 (50%) | 65/123 (53%) | 62/120 (52%) | 62/119 (52%) | 56/119 (47%) | 66/122 (54%) | 67/118 (57%) | 67/115 (58%) | 76/112 (68%) | 76/120 (63%) | 80/112 (71%) | 62/104 (60%) |
| ȃCorrectly identified: relapse (log[MBL+1]) | 2/3 | 4/4 | 3/3 | 2/3 | 3/3 | 4/4 | 4/4 | 4/4 | 4/4 | 4/4 | 2/3 | 2/3 | 3/4 |
Full data can be found in Supplementary Tables 2 and 3. Data are displayed for up to week 14, since no significant changes were observed after this timepoint. The cured vs relapse groups are compared using the Kruskal-Wallis test followed by a post hoc Dunn test to obtain the pairwise difference between groups. The classification of no./No. of correctly identified cured patients/correctly identified relapse patients was done using the upper bound of the 95% credible interval for (log[Mbl + 1]) of the cured group. For TTP, classification the lower bound of the 95% credible interval for (log[TTP]) of the cured group was used. Varying numbers between visits reflect availability of results. Results may be missing due to unavailability of sample, or in the case of MGIT TTP, culture contamination. P values in bold are smaller than 0.05, indicating statistical significance.
Abbreviations: MBL, molecular bacterial load; MBLA, molecular bacterial load assay; MGIT, mycobacteria growth indicator tube; TB-MBLA, tuberculosis molecular bacterial load assay; TTP, time to positivity.