Table 1.
Baseline characteristics stratified by gender and treatment group. Baseline characteristics of patients in the per-protocol population. Numbers are N (%) unless otherwise stated
| Characteristics | Control group (N = 510) | Isoniazid group (N = 514) | Ethambutol group (N = 524) | All patients (N = 1548) | ||||
|---|---|---|---|---|---|---|---|---|
| Sex | Male (N = 356) | Female (N = 154) | Male (N = 351) | Female (N = 163) | Male (N = 369) | Female (N = 155) | Male (N = 1076) | Female (N = 472) |
| Age group* | ||||||||
| ≤ 30 years | 155 (44) | 89 (58) | 170 (48) | 84 (52) | 161 (44) | 80 (52) | 486 (45) | 253 (54) |
| > 30 years | 201 (56) | 65 (42) | 181 (52) | 79 (48) | 208 (56) | 75 (48) | 590 (55) | 219 (46) |
| Weight group* | ||||||||
| < 40 kg | 14 (4) | 36 (23) | 14 (4) | 30 (18) | 29 (8) | 29 (19) | 57 (5) | 95 (20) |
| 40–45 kg | 45 (13) | 35 (23) | 54 (15) | 36 (22) | 54 (15) | 28 (18) | 153 (14) | 99 (21) |
| > 45–55 kg | 163 (46) | 43 (28) | 159 (45) | 51 (31) | 149 (40) | 55 (35) | 471 (44) | 149 (32) |
| > 55 kg | 134 (38) | 40 (26) | 124 (35) | 46 (28) | 137 (37) | 43 (28) | 395 (37) | 129 (27) |
| BMI | ||||||||
| < 18.5 | 196 (55) | 71 (46) | 199 (57) | 73 (45) | 211 (57) | 64 (41) | 606 (56) | 208 (44) |
| ≥ 18.5 | 160 (45) | 83 (54) | 152 (43) | 90 (55) | 158 (43) | 91 (59) | 470 (44) | 264 (56) |
| Race or ethnic group*‡ | ||||||||
| Black | 171 (48) | 67 (44) | 150 (43) | 60 (37) | 173 (47) | 64 (41) | 494 (46) | 191 (40) |
| Asian | 109 (31) | 51 (33) | 107 (30) | 47 (29) | 119 (32) | 42 (27) | 335 (31) | 140 (30) |
| Mixed race or other | 76 (21) | 36 (23) | 94 (27) | 56 (34) | 77 (21) | 49 (32) | 247 (23) | 141 (30) |
| Smoking status* | ||||||||
| Never | 133 (37) | 113 (73) | 121 (34) | 110 (67) | 127 (34) | 103 (66) | 381 (35) | 326 (69) |
| Past | 105 (29) | 14 (9) | 100 (28) | 11 (7) | 117 (32) | 17 (11) | 322 (30) | 42 (9) |
| Current | 118 (33) | 27 (18) | 130 (37) | 42 (26) | 125 (34) | 35 (23) | 373 (35) | 104 (22) |
| HIV positivity* | 21 (6) | 17 (11) | 23 (7) | 14 (9) | 17 (5) | 18 (12) | 61 (6) | 49 (10) |
| Cavitation*ǁ | 268 (75) | 100 (65) | 244 (70) | 113 (69) | 264 (72) | 103 (66) | 776 (72) | 316 (67) |
| Area of lung involvement (%, (SD)) | 21.5 (12.5) | 20.1 (12.4) | 20.9 (13.1) | 19.2 (12.1) | 20.9 (12.2) | 19.7 (11.0) | 21.1 (12.6) | 19.7 (11.9) |
| Smear grading | ||||||||
| Neg | 14 (4) | 7 (5) | 14 (4) | 5 (3) | 17 (5) | 7 (5) | 45 (4) | 19 (4) |
| 1+ | 32 (9) | 15 (10) | 24 (7) | 17 (10) | 25 (7) | 14 (9) | 81 (8) | 46 (10) |
| 2+ | 43 (12) | 19 (12) | 52 (15) | 26 (16) | 62 (17) | 22 (14) | 157 (15) | 67 (14) |
| 3+ | 86 (24) | 42 (27) | 79 (23) | 37 (23) | 82 (22) | 32 (21) | 247 (23) | 111 (24) |
| 4+ | 181 (51) | 71 (46) | 182 (52) | 78 (48) | 183 (50) | 80 (52) | 546 (51) | 229 (49) |
| LJ | ||||||||
| Positive | 283 (79) | 117 (76) | 277 (79) | 137 (84) | 294 (80) | 132 (85) | 854 (81) | 386 (82) |
| Negative | 33 (9) | 14 (9) | 25 (7) | 12 (7) | 31 (8) | 4 (3) | 89 (8) | 30 (6) |
| Contaminated | 29 (8) | 16 (10) | 38 (11) | 14 (9) | 33 (9) | 16 (10) | 100 (9) | 46 (10) |
| Indeterminate | 11 (3) | 7 (5) | 11 (3) | 0 (0) | 11 (3) | 3 (2) | 33 (3) | 10 (2) |
| TTD (median [IQR]) | 14 [14–21] | 14 [14–21] | 14 [14–25] | 14 [14–21] | 21 [14–28] | 14 [14–21] | 14 [14–21] | 14 [14–21] |
| MGIT | ||||||||
| Positive | 329 (92) | 141 (92) | 319 (93) | 157 (96) | 332 (90) | 147 (95) | 980 (93) | 445 (94) |
| Negative | 5 (1) | 2 (1) | 4 (1) | 0 (0) | 7 (2) | 2 (1) | 16 (2) | 4 (1) |
| Contaminated | 11 (3) | 4 (3) | 10 (3) | 6 (4) | 15 (4) | 3 (2) | 36 (3) | 13 (3) |
| False positive | 2 (1) | 0 (0) | 5 (1) | 0 (0) | 4 (1) | 0 (0) | 11 (1) | 0 (0) |
| Indeterminate | 9 (3) | 7 (5) | 13 (4) | 0 (0) | 11 (3) | 3 (2) | 13 (1) | 10 (2) |
| TTP (median [IQR]) | 4.81 [3.71–6.66] | 5.13 [3.79–6.79] | 4.92 [3.70–6.39] | 5.04 [4.03–6.43] | 4.83 [3.67–6.58] | 4.73 [3.70–6.50] | 4.83 [3.71–6.50] | 5.04 [3.88–6.46] |
p values for categorical variables are calculated using chi-squared test and for the continuous variable using Mann-Whitney U test
HIV human immunodeficiency virus, TTD time to detect a positive culture in days on LJ media, TTP time to detect a positive culture in days in MGIT, IQR interquartile range
*Males and females were significantly different at baseline for weight, age, race, smoking, HIV, cavitation, area of lung involvement and LJ TTD; p values were ≤ 0.001, 0.002, 0.013, ≤ 0.001, 0.001, 0.022, 0.05 and 0.04 respectively
‡Race or ethnic group was reported by the investigator. Asian category included both South Asians and East Asians. Mixed race or other included mixed race, coloured and Caucasian
ǁCavitation status was missing for 148 patients