. 2015 Aug 14;59(9):5455–5462. doi: 10.1128/AAC.00117-15

TABLE 2.

Bivariate analysis of resistance to ethambutol and M. tuberculosis drug sensitivity profiles

Drug resistance of M. tuberculosis^b	Resistant to at least one drug		Resistance results by group^a				Odds ratio^c	95% confidence interval	P value^d
	Resistant to at least one drug		EMB^r		EMB^s
	No. (n = 110)	%	No. (n = 61)	%	No. (n = 49)	%
INH^r	90	82	53	87	37	76	2.2	0.8–5.8	0.12
RIF^r	75	68	49	80	26	53	3.6	1.6–8.4	<0.01
STR^r	69	63	40	66	29	59	1.3	0.6–2.9	0.49
PZA^r	43	39	34	56	9	18	5.6	2.3–13.6	<0.001
MDR-TB (INH+RIF)	72	65	49	80	23	47	4.6	2.0–11.0	<0.001
≥3 drugs	65	59	51	84	14	29	12.8	5.0–32.0	<0.001

EMB^r, ethambutol resistant; EMB^s, ethambutol sensitive.

INH^r, isoniazid resistant; RIF^r, rifampin resistant; PZA^r, pyrazinamide resistant; EMB^r, ethambutol resistant; STR^r, streptomycin resistant.

The OR was calculated by associating the risk of different drug resistances with ethambutol resistance. The opposite event of each variable was used like a comparison group (INH^r/INH^s; RIF^r/RIF^s; STR^r/STR^s; PZA^r/PZA^s; MDR-TB (INH+RIF)/INH^s+RIF^s; ≥3 drugs/resistant to 1 or 2 drug).

By chi-square test. P values of <0.05 are significant.