Table 2 Risk factors for TB incidence after IPT (intention-to-treat)

Sex

Male

16,704 (95.8)

23,036

523

1

0.08

1

0.73

Female

741 (4.2)

999

18

0.67 (0.42–1.08)

1.09 (0.67–1.80)

Age, years ^b

≤29

2,370 (13.6)

3,221

30

1

<0.001

1

<0.001

30–39

4,677 (26.8)

6,660

131

2.13 (1.43–3.17)

2.18 (1.46–3.25)

40–49

7,363 (42.2)

10,291

276

2.81 (1.92–4.10)

2.84 (1.92–4.18)

≥50

3,035 (17.4)

3,863

104

2.69 (1.79–4.06)

2.77 (1.81–4.23)

Country of origin

South Africa

10,008 (57.4)

13,729

284

1

0.001

1

0.09

Lesotho

4,736 (27.2)

6,471

190

1.40 (1.17–1.68)

1.15 (0.95–1.40)

Mozambique

1,777 (10.2)

2,499

40

0.84 (0.60–1.18)

0.79 (0.57–1.11)

Other

917 (5.3)

1,327

27

1.06 (0.71–1.58)

0.82 (0.54–1.24)

Years in workforce ^c

0–9

4,683 (26.9)

6,391

85

1

<0.001

10–19

4,753 (27.3)

6,856

147

1.68 (1.28–2.20)

20–29

5,511 (31.7)

7,608

217

2.11 (1.64–2.71)

≥30

2,446 (14.1)

3,107

90

2.12 (1.57–2.86)

Type of work

Surface

1,537 (8.8)

2,165

30

1

0.002

1

0.002

Underground

15,836 (91.2)

21,762

508

1.71 (1.18–2.48)

1.75 (1.20–2.54)

Type of housing

Hostel

10,239 (58.7)

14,378

364

1

<0.001

1

0.004

Other

7,206 (41.3)

9,657

177

0.67 (0.55–0.80)

0.74 (0.61–0.91)

Previous TB

No

15,427 (88.5)

21,413

430

1

<0.001

1

<0.001

Yes

2,005 (11.5)

2,605

111

2.08 (1.69–2.57)

1.89 (1.52–2.35)

Self-reported ART use

No

16,956 (97.3)

23,386

523

1

0.42

1

0.64

Yes

471 (2.7)

625

17

1.23 (0.76–1.99)

0.89 (0.54–1.46)

Number of

1–2

4,640 (26.6)

6,513

159

1

0.001

1

<0.001

IPT prescriptions ^d,e

3–5

1,855 (10.6)

2,557

56

0.86 (0.64–1.17)

0.81 (0.59–1.09)

6+

10,951 (62.8)

14,967

326

0.79 (0.65–0.97)

0.63 (0.51–0.77)