TABLE 3.

Proportion of culture-negative results by smear grading at treatment follow-up among TB patients enrolled in clinical trials at NIRT, India, 2000–2012

Smear grade*	Culture-negative results/cultures performed
	Month 1 n/N (%)	Month 2 n/N (%)	Month 3 n/N (%)	Month 4 n/N (%)	Month 5 n/N (%)	Month 6 n/N (%)
1+	149/563 (27)	252/333 (76)	145/184 (79)	89/122 (73)	43/65 (66)	40/67 (60)
2+	4/57 (7)	10/20 (50)	5/14 (36)	2/9 (22)	2/11 (18)	1/6 (17)
3+	1/5 (20)	0/1 (0)	0/3 (0)	0/2 (0)	0/1 (0)	0/0 (0)

^*1+: <6 bacilli/high power field (HPF); 2+: 6–100 bacilli/HPF; 3+: >100 bacilli/HPF or large clumps.

TB = tuberculosis; NIRT = National Institute for Research in Tuberculosis.