Table 3 Risk factors stratified by time after intended end of isoniazid preventive therapy (intention-to-treat)

Sex

Male

15,759

344

1

7,277

179

1

0.15

Female

709

15

0.82 (0.49–1.38)

290

3

0.35 (0.11–1.11)

Age, years

≤29

2,229

18

1

992

12

1

0.54

30–39

4,465

81

2.27 (1.36–3.79)

2,196

50

1.90 (1.01–3.56)

40–49

6,995

189

3.27 (2.01–5.30)

3,295

87

2.14 (1.17–3.91)

≥50

2,779

71

3.01 (1.79–5.06)

1,085

33

2.42 (1.25–4.70)

Years in workforce

0–9

4,436

58

1

1,956

27

1

0.15

10–19

4,543

84

1.48 (1.06–2.08)

2,314

63

2.05 (1.30–3.22)

20–29

5,213

155

2.23 (1.65–3.02)

2,395

62

1.86 (1.18–2.92)

≥30

2,229

61

2.03 (1.41–2.91)

878

29

2.35 (1.39–3.97)

Type of work

Surface

1,465

20

1

700

10

1

0.98

Underground

14,932

339

1.71 (1.09–2.69)

6,830

169

1.72 (0.91–3.27)

Type of housing

Hostel

9,681

236

1

4,697

128

1

0.57

Other

6,787

123

0.69 (0.55–0.86)

2,870

54

0.62 (0.45–0.85)

Previous TB

No

14,618

281

1

6,795

149

1

0.63

Yes

1,838

78

2.15 (1.68–2.77)

767

33

1.93 (1.32–2.81)

Self-reported ART use

No

16,013

346

1

7,373

177

1

0.82

Yes

439

12

1.28 (0.72–2.27)

186

5

1.13 (0.46–2.75)

Number of IPT prescriptions

1–2

4,321

99

1

2,192

60

1

0.86

3–5

1,715

36

0.88 (0.60–1.29)

842

20

0.84 (0.50–1.39)

6+

10,433

224

0.82 (0.65–1.05)

4,534

102

0.79 (0.42–1.46)