Table 3. Treatment patterns among MDR TB patients, by 6 month intervals of treatment (n = 583).

Category Characteristics				Treatment Time
	Interruption Duration		Interruption Variability		0–6 mos. (n = 583)	6–12 mos. (n = 513)			12–18 mos. (n = 479)	18–24 mos. (n = 424)	Overall (0–24 mos.) (n = 583)
1	Short	Small (Regular)			0 (0.0)		40 (7.8)		73 (15.2)	25 (5.9)	138 (23.7)
2	Short	Large (Sporadic)			200 (34.3)		160 (31.2)		133 (27.8)	101 (23.8)	135 (23.2)
3	Long	Regular			0 (0.0)			0 (0.0)	1 (0.2)	2 (0.5)	12 (2.1)
4	Long	Sporadic			213 (36.5)		218(42.5)		192 (40.1)	140 (33.0)	256 (43.9)
	No missed doses during period				170 (29.2)	95 (18.5)			80 (16.7)	160 (37.4)	41 (7.0)

Four categories of treatment interruption patterns based on the patients in the period that had at least one treatment interruption (missed dose) during that period. Cut-offs to create categories based on the median of interruption characteristics (individual mean interruption length in days and the individual standard deviation of the interruption length in days) during the period, wherein individual values below and inclusive of the median value denoted short or small/regular and values exceeding the median cut-off were categorized as long or large/sporadic. The pooled median of individual mean days of interruption and standard deviation of interruption used for cut-offs was 1.14, 0 for 0–6 months; 1.21, 0.38 for 6–12 months; 1.28, 0.50 for 12–18 months, and 1.33, 0.51 for 18–24 months. N in parentheses at the top of each column reflects number of patients who were still on treatment at the beginning of the 6 month period.