Table 3. Factors associated with mortality among adult cases on drug resistant tuberculosis treatment in Eastern Cape, South Africa; 2011 to 2013.

DR TB Characteristic	Univariate Analysis		Multivariable Analysis
	IRR (95% CI)	P-value a	aIRR (95% CI)	P-value a
HIV ART Status
Negative	Ref		Ref
Co-infected on ART	1.4 (1.3–1.5)	<0.001	1.4 (1.3–1.5)	<0.001
Co-infected not on ART	3.2 (2.9–3.5)	<0.001	3.3 (2.9–3.8)	<0.001
Status unknown	1.6 (1.4–1.9)	<0.001	1.1 (0.8–1.5)	0.546
Age
18–29	Ref		Ref
30–44	1.2 (1.1–1.3)	0.001	1.1 (1.0–1.2)	0.107
45–59	1.2 (1.1–1.2)	0.027	1.1 (1.0–1.2)	0.101
60 +	1.4 (1.2–1.7)	<0.001	1.7 (1.5–2.0)	<0.001
DR-TB type
MDR-TB	Ref		Ref
XDR-TB	1.8 (1.7–1.9)	<0.001	1.6 (1.5–1.7)	<0.001
Previous Drug History
New	Ref		Ref
History of1st line drugs	1.3 (1.3–1.4)	<0.001	1.2 (1.1–1.3)	0.002
History of 2nd line drugs	1.9 (1.8–2.1)	<0.001	1.4 (1.3–1.5)	<0.001
Treatment Initiation Site
Community	Ref		Ref
DR-TB Hospital	1.9 (1.7–2.0)	<0.001	1.7 (1.5–1.8)	<0.001
Registration Year
2011	Ref		Ref
2012	1.0 (0.9–1.0)	0.501	1.0 (1.0–1.1)	0.498
2013	0.9 (0.8–0.9)	0.004	1.1 (1.1–1.2)	0.009

HIV, Human Immunodeficiency Virus; ART, Anti-retroviral therapy; DR-TB, drug resistant tuberculosis; aIRR, adjusted incidence risk ratio,

^a P-value calculated using modified Poisson regression.