Table 3. Unadjusted and multivariate analyses of risk factors for mortality during ART.

		Unadjusted analysis			Multivariate analysis
		IRR	95% CI	p-value	IRR	95% CI	p-value
Age at enrolment a		1.04	1.02–1.06	<0.001	1.04	1.02–1.06	<0.001
Gender	F	1			1
	M	1.73	1.31–2.28	<0.001	1.09	0.80–1.47	0.571
WHO stage at enrolment	1 & 2	1			1
	3	2.88	1.65–5.02	<0.001	1.77	0.97–3.19	<0.001
	4	5.50	3.13–9.67		3.41	1.87–6.24
Baseline CD4 cell count (cells/µl)	≥150	1			1
	100–149	1.08	0.69–1.69		0.83	0.57–1.21
	50–99	1.30	0.86–1.97	<0.001	1.52	0.96–2.43	0.020
	<50	2.04	1.39–2.99		1.67	1.04–2.65
Baseline viral load (log10 copies/ml)	<5	1			1
	≥5	1.64	1.24–2.17	0.001	1.34	1.01–1.79	0.040
Duration of ART (months)	0–12	1			1
	12–24	0.23	0.15–0.36		0.61	0.38–0.98
	24–36	0.19	0.12–0.31		0.62	0.36–1.07
	36–48	0.21	0.13–0.34	<0.001	0.66	0.37–1.16	0.123
	48–60	0.14	0.07–0.26		0.51	0.26–1.02
	>60	0.13	0.07–0.25		0.45	0.21–0.96
Updated CD4 cell count (cells/µl) d	>500	1			1
	401–500	1.00	0.40–2.52		0.93	0.37–2.35
	301–400	2.08	1.01–4.28		1.77	0.84–3.71
	201–300	2.85	1.45–5.60	<0.001	1.87	0.90–3.87	<0.001
	101–200	6.66	3.60–12.31		2.98	1.44–6.20
	0–100	31.84	17.87–56.74		10.41	4.69–23.14
Updated viral load (copies/ml) d	<1000	1			1
	≥1000	8.46	6.41–11.17	<0.001	2.74	1.86–4.04	<0.001
Past History of TB at baseline b	No	1
	Yes	1.87	1.41–2.47	<0.001
Prevalent TB at baseline c	No	1			1
	Yes	1.85	1.40–2.44	<0.001	1.67	1.23–2.25	0.001
Incident TB	No	1			1
	Yes	1.80	1.33–2.43	<0.001	2.70	1.91–3.81	<0.001

ART, antiretroviral therapy; TB, tuberculosis; IRR, incident rate ratio; CI, confidence interval. All p-values were calculated using the likelihood ratio test.

^aAge is included as continuous variable, the IRR represents a 1 year increase in age.

^bincludes all TB episodes where anti-TB treatment was completed prior to ART enrolment.

^cTB episodes where patients are taking anti-TB treatment at ART initiation.

^dCD4 cell counts and viral load are time-updated variables using serial measurements taken during ART.