Table 3.

Cox regression modelling of baseline characteristics and incident TB

		Unadjusted analyses		Adjusted analyses
		HR (95% CI)	P	AHR (95% CI)	P
Baseline CD4* (cells/μL)	> 500	0.13 (0.06 – 0.32)	<0.001	0.15 (0.06 – 0.36)	<0.001
	350 – 500	0.41 (0.24 – 0.68)		0.45 (0.27 – 0.77)
	200 – 350	0.33 (0.20 – 0.56)		0.36 (0.21 – 0.60)
	0 – 200	1.00		1.00
Gender	Male	2.58 (1.73 – 3.85)	<0.001	2.16 (1.41 – 3.30)	<0.001
	Female	1.00		1.00
Clinic	Metro 1	1.00	0.212	1.00	0.047
	Metro 2	1.26 (0.77 – 2.05)		1.54 (0.89 – 2.66)
	Rural 1	1.63 (0.95 – 2.79)		2.17 (1.19 – 3.97)
Age category (Years)	15–25	0.84 (0.47 – 1.49)	0.465	1.18 (0.66 – 2.13)	0.951
	26 – 35	1.00
	36–45	1.38 (0.84 – 2.27)		1.28 (0.68 – 1.87)
	46–55	1.34 (0.69 – 2.61)		1.22 (0.62–2.38)
	>55	1.52 (0.47 – 4.89)		1.34 (0.41 – 4.38)
Pregnant at baseline**	Yes	0.51 (0.16 – 1.62)	0.207	0.79 (0.23 – 2.46)	0.727
Baseline TB***	Yes	1.50 (0.80 – 2.82)	0.155	0.83 (0.41 – 1.53)	0.487
Previous ART exposure of > 3 months	Yes	3.94 (1.82 – 8.52)	0.001	3.28 (1.49 – 7.2)	0.003
Year ART start	2014	0.97 (0.62 – 1.53)	0.906	0.75 (0.45 – 1.26)	0.272
	2015	1.00		1.00

All individuals were included in this analysis regardless of baseline TB status. Follow up time is therefore not equal - time on ART as follow up for individuals on TB treatment at ART initiation was delayed until the estimated end of TB treatment (6 months after TB treatment initiation). Baseline characteristics for inclusion in multivariate modelling were chosen based on clinical significance. For baseline characteristics with more than two categories likelihood ratios were used - estimate P values for hazard of incident TB. Baseline CD4 count was the most recent CD4 count completed in the 6 months prior - ART initiation.

^***All individuals initiating ART are screened for pregnancy at baseline. Baseline TB was defined as having started TB treatment within the 6 months prior - ART initiation.