Table 3.
Treatment Outcomes in Relation to the Number of Effective Drugs, Untested Drugs, Ineffective Drugs, Total Number of Drugs, and Individual Drugs With Which Patients Were Treated, Comparing Successful and Poor Outcomes Among Patients With Known Outcomes and Comparing Patients With Known Outcomes With Those Lost to Follow-up
| Drug Category | Successful vs Poor Treatment Outcomes Among Patients With Known Outcomes (n = 973) |
Known Outcomes vs Lost to Follow-up (n = 1205)a |
|||||
|---|---|---|---|---|---|---|---|
| Successful Outcome, No. (%) (n = 722) | Poor Outcome, No. (%) (n = 251) | P Valueb | Risk Ratio (95% CI) for Treatment Success | Known Outcomes, No. (%) (n = 973) | Lost to Follow-up, No. (%) (n = 232) | P Valueb | |
| No. of effective drugs in patient's treatmentc | |||||||
| 0–1 | 32 (41.6) | 45 (58.4) | <.001d | Reference | 77 (74.0) | 27 (26.0) | .68d |
| 2 | 140 (61.7) | 87 (38.3) | 1.49 (1.11–1.96) | 227 (82.6) | 48 (17.5) | ||
| 3 | 272 (77.3) | 80 (22.7) | 1.85 (1.41–2.44) | 352 (81.7) | 79 (18.3) | ||
| 4 | 242 (87.1) | 36 (13.0) | 2.08 (1.61–2.78) | 278 (80.6) | 67 (19.4) | ||
| 5–6 | 36 (92.3) | 3 (7.7) | 2.22 (1.67–2.94) | 39 (78.0) | 11 (22.0) | ||
| No. of untested drugs in patient's treatmente | |||||||
| 0 | 155 (68.0) | 73 (32.0) | .62d | Reference | 228 (83.5) | 45 (16.5) | .008d |
| 1 | 469 (77.4) | 137 (22.6) | 1.14 (1.03–1.25) | 606 (81.8) | 135 (18.2) | ||
| 2 | 87 (73.7) | 31 (26.3) | 1.09 (.94–1.25) | 118 (72.4) | 45 (27.6) | ||
| 3 | 11 (52.4) | 10 (47.6) | 0.77 (.51–1.18) | 21 (75.0) | 7 (25.0) | ||
| No. of ineffective drugs in patient's treatmentf | |||||||
| 0 | 366 (82.3) | 79 (17.8) | <.001d | Reference | 445 (78.9) | 119 (21.1) | .07d |
| 1 | 264 (74.4) | 91 (25.6) | 0.90 (.84–.97) | 355 (81.4) | 81 (18.6) | ||
| 2 | 70 (57.4) | 52 (42.6) | 0.70 (.60–.82) | 122 (83.6) | 24 (16.4) | ||
| 3 | 22 (43.1) | 29 (56.9) | 0.52 (.38–.72) | 51 (86.4) | 8 (13.6) | ||
| Total No. of drugs in patient's treatment | |||||||
| ≤3 | 28 (56.0) | 22 (44.0) | .009d | Reference | 50 (75.8) | 16 (24.2) | .49d |
| 4 | 84 (70.0) | 36 (30.0) | 1.25 (.95–1.64) | 120 (81.6) | 27 (18.4) | ||
| 5 | 313 (76.2) | 98 (23.8) | 1.35 (1.05–1.75) | 411 (83.0) | 84 (17.0) | ||
| 6 | 185 (74.6) | 63 (25.4) | 1.33 (1.03–1.72) | 248 (78.5) | 68 (21.5) | ||
| 7 | 80 (74.1) | 28 (25.9) | 1.32 (1.01–1.72) | 108 (82.4) | 23 (17.6) | ||
| ≥8 | 32 (88.9) | 4 (11.1) | 1.59 (1.20–2.08) | 36 (72.0) | 14 (28.0) | ||
| Effectiveness of treatment by drug | |||||||
| Pyrazinamideg | |||||||
| Effective | 215 (84.6) | 39 (15.3) | <.001 | 1.20 (1.11–1.30) | 254 (76.0) | 80 (23.9) | .04 |
| Not effective | 333 (70.4) | 140 (29.6) | Reference | 473 (81.7) | 106 (18.3) | ||
| Unknown | 174 (70.7) | 72 (29.3) | … | … | 246 (84.2) | 46 (15.7) | … |
| Ethambutol | |||||||
| Effective | 260 (80.0) | 65 (20.0) | .003 | 1.12 (1.04–1.21) | 70 (17.7) | 325 (82.3) | .35 |
| Not effectiveh | 462 (71.3) | 186 (28.7) | 162 (20.0) | 648 (80.0) | |||
| Streptomycin | |||||||
| Effective | 130 (78.8) | 35 (21.2) | <.001 | 1.75 (1.43–2.15) | 45 (21.4) | 165 (78.6) | .98 |
| Not effectivei | 59 (45.0) | 72 (55.0) | 36 (21.6) | 131 (78.4) | |||
| Kanamycin | |||||||
| Effective | 436 (81.5) | 99 (18.5) | <.001 | 1.81 (1.49–2.2) | 129 (19.4) | 535 (80.6) | .54 |
| Not effectivei | 59 (45.0) | 72 (55.0) | 36 (21.6) | 131 (78.4) | |||
| Amikacin | |||||||
| Effective | 111 (65.7) | 58 (34.3) | <.001 | 1.46 (1.17–1.81) | 30 (15.1) | 169 (84.9) | .11 |
| Not effectivei | 59 (45.0) | 72 (55.0) | 36 (21.6) | 131 (78.4) | |||
| Capreomycin | |||||||
| Effective | 172 (74.8) | 58 (25.2) | <.001 | 1.66 (1.35–2.04) | 48 (17.3) | 230 (82.7) | .26 |
| Not effectivei | 59 (45.0) | 72 (55.0) | 36 (21.6) | 131 (78.4) | |||
| Any injectable drug | |||||||
| Effective | 663 (78.7) | 179 (21.3) | <.001 | 1.75 (1.44–2.12) | 196 (18.9) | 842 (81.1) | .42 |
| Not effectivei | 59 (45.0) | 72 (55.0) | 36 (21.6) | 131 (78.4) | |||
| Ciprofloxacin | |||||||
| Effective | 141 (75.0) | 47 (25.0) | <.001 | 1.60 (1.31–1.97) | 55 (22.6) | 188 (77.4) | .13 |
| Not effectivej | 58 (46.8) | 66 (53.2) | 24 (16.2) | 124 (83.8) | |||
| Levofloxacin | |||||||
| Effective | 46 (85.2) | 8 (14.8) | <.001 | 1.82 (1.46–2.27) | 13 (19.4) | 54 (80.6) | .57 |
| Not effectivej | 58 (46.8) | 66 (53.2) | 24 (16.2) | 124 (83.8) | |||
| Moxifloxacin | |||||||
| Effective | 175 (78.5) | 48 (21.5) | <.001 | 1.68 (1.37–2.05) | 43 (16.2) | 223 (83.8) | .99 |
| Not effective j | 58 (46.8) | 66 (53.2) | 24 (16.2) | 124 (83.8) | |||
| Ofloxacin | |||||||
| Effective | 422 (76.3) | 131 (23.7) | <.001 | 1.63 (1.34–1.98) | 127 (18.7) | 553 (81.3) | .48 |
| Not effectivej | 58 (46.8) | 66 (53.2) | 24 (16.2) | 124 (83.8) | |||
| Any FQ | |||||||
| Effective | 664 (78.2) | 185 (21.8) | <.001 | 1.67 (1.38–2.02) | 208 (19.7) | 849 (80.3) | .32 |
| Not effectivej | 58 (46.8) | 66 (53.2) | 24 (16.2) | 124 (83.8) | |||
| Thioamidesk | |||||||
| Effective | 579 (75.5) | 188 (24.5) | .08 | 1.09 (.98–1.2) | 192 (20.0) | 767 (80.0) | .18 |
| Not effectiveh | 143 (69.4) | 63 (30.6) | 40 (16.3) | 206 (83.7) | |||
| p-Aminosalicylic acid | |||||||
| Effective | 413 (78.7) | 112 (21.3) | <.001 | 1.14 (1.06–1.23) | 113 (17.7) | 525 (82.3) | .15 |
| Not effectiveh | 309 (69.0) | 139 (31.0) | 119 (21.0) | 448 (79.0) | |||
| No. of effective companion drugsl | |||||||
| 0 | 48 (56.5) | 37 (43.5) | <.001d | Reference | 18 (17.5) | 85 (82.5) | .63 |
| 1 | 210 (71.4) | 84 (28.6) | 1.27 (1.03–1.54) | 80 (21.4) | 294 (78.6) | ||
| ≥2 | 464 (78.1) | 130 (21.9) | 1.39 (1.14–1.67) | 134 (18.4) | 594 (81.6) | ||
Abbreviations: CI, confidence interval; FQ, fluoroquinolone.
a Risk ratios (95% CIs) for the comparison of patients with known outcomes versus those lost to follow-up are not presented because most of them were not statistically significant.
b For ordinal variables, the overall P value for trend is presented in the row for the reference cell.
c The number of effective drugs is the number of drugs with which the patient was treated that were demonstrated to be effective based on Centers for Disease Control and Prevention (CDC) drug susceptibility test (DST) results.
d Overall P value for trend.
e The number of untested drugs is the number of drugs with which the patient was treated that were not tested at the CDC: cycloserine or terizidone (considered the same drug), thioacetazone, and all World Health Organization group 5 drugs (amoxicillin plus clavulanic acid, clarithromycin, clofazimine, imipenem plus cilastin, and linezolid).
f The number of ineffective drugs is the number of drugs with which the patient was treated that were later demonstrated to be ineffective based on CDC DST results. Isoniazid and rifampicin were not included in this number because all patients had isoniazid and rifampicin resistance by definition.
g Phenotypic DST and pncA gene sequencing for pyrazinamide susceptibility have not yet been completed. The effectiveness of pyrazinamide is based on combining all available results from CDC and local laboratories that all used the Mycobacterial Growth Indicator Tube 960 method. Not all patients’ initial isolates were tested for pyrazinamide. The “not effective” category means either that the patient did not receive pyrazinamide or that any available DST result indicated resistance. The “unknown” category means that DST results were not available.
h In the drug-by-drug listing for ethambutol, thioamides, and para-aminosalicylic acid, effective means CDC DST results showed susceptibility and the patient received the drug; the “not effective” category, means CDC DST results showed resistance or the patient did not receive the drug.
i In the drug-by-drug listing for injectable drugs, and for the injectable drugs as a group, the “not effective” category means the patient did not receive any effective injectable drug; that is, either the patient did not receive the drug or the CDC DST results showed resistance to all injectable drugs.
j In the drug-by-drug listing for FQs, and for FQs as a group, the “not effective” category means the patient did not receive any effective FQ; that is, either the patient did not receive the drug or the CDC DST results showed resistance to all FQs tested.
k Thioamides include ethionamide and prothionamide, analyzed together as the same drug.
l Companion drugs included ethambutol, thioamides, and para-aminosalicylic acid.