TABLE 1.
Pattern of serial smear results during TB treatment, by month of follow-up, among patients enrolled in clinical trials at NIRT, India, 2000–2012*
| Month 1 n (%) | Month 2 n (%) | Month 3 n (%) | Month 4 n (%) | Month 5 n (%) | Month 6 n (%) | |
| Two overnight specimens | (n = 489) | (n = 484) | (n = 475) | (n = 455) | (n = 450) | (n = 419) |
| NN | 201 (41) | 308 (64) | 369 (78) | 386 (85) | 411 (91) | 380 (91) |
| NP | 50 (10) | 40 (8) | 28 (6) | 16 (4) | 7 (2) | 16 (4) |
| PN | 53 (11) | 43 (9) | 32 (7) | 25 (5) | 14 (3) | 10 (2) |
| PP | 185 (38) | 93 (19) | 46 (10) | 28 (6) | 18 (4) | 13 (3) |
| Spot and first overnight specimen | (n = 485) | (n = 480) | (n = 474) | (n = 450) | (n = 447) | (n = 416) |
| NN | 218 (45) | 321 (67) | 380 (80) | 388 (86) | 406 (91) | 384 (92) |
| NP | 99 (20) | 67 (14) | 46 (10) | 28 (6) | 19 (4) | 13 (3) |
| PN | 30 (6) | 24 (5) | 16 (3) | 10 (2) | 9 (2) | 9 (2) |
| PP | 138 (28) | 68 (14) | 32 (7) | 24 (5) | 13 (3) | 10 (2) |
| Spot and second overnight specimen | (n = 485) | (n = 480) | (n = 474) | (n = 450) | (n = 447) | (n = 416) |
| NN | 226 (47) | 319 (66) | 384 (81) | 393 (87) | 414 (93) | 381 (92) |
| NP | 91 (19) | 69 (14) | 42 (9) | 23 (5) | 11 (2) | 16 (4) |
| PN | 25 (5) | 29 (6) | 16 (3) | 14 (3) | 8 (2) | 6 (1) |
| PP | 143 (29) | 63 (13) | 32 (7) | 20 (4) | 14 (3) | 13 (3) |
*
The variation in denominators at each month is due to the varying availability of culture and smear results of spot and overnight specimens. Percentages may not total 100% due to rounding.
TB = tuberculosis; NIRT = National Institute for Research in Tuberculosis; NN = negative-negative; NP = negative-positive; PN = positive-negative; PP = positive-positive.