Table 3. Studies comparing isoniazid treatment with no treatment in HIV-infected populations*

Author, country, dates

Population

Intervention/ comparison; blinding

Enrolled (n) INH/control

Follow up; loss to follow-up; overall or INH vs. control

TB cases: culture positive/total (%)

Definition of INH resistance

Resistant cases/total tested (% culture positive tested)

Risk for resistant TB/1,000

RR (95% CI)

INH

Controls

INH

Controls

INH

Controls

Randomized controlled trials

Gordin, USA, 1991–1996 (30)

Clinic attendees; med. CD4 233/247

6 mo INH 300 mg daily vs. placebo; double blind

260/257

34 mo/33 mo; 6.2% vs. 7%

NS/3

NS/6

NS

0/3 (NS)

0/5 (NS)

1.92†

1.94†

0.99 (0.06–6,298.19)

Hawken, Kenya, 1992–1997 (31)

Clinic or VCT attendees; med. CD4 321.5/346

6 mo INH 300 mg daily/placebo; double blind

342/342

Med. 1.83 y (range 0–3.41); 32% vs. 27.3% not seen in final 6 m

19/25 (76)

22/23 (95.7)

Growth on 0.2 μg/mL INH >1% growth on control medium

2/17 (90)

0/21 (96)

10.05†

1.46†

6.88 (0.01–3,882.85)

Mwinga, Zambia, 1992–1996 (33)

VCT attendees

6 mo INH 900 mg twice weekly/placebo; double blind

350/352

Med. 1.8 y; 32.4% vs. 30.3% not seen in final 6 m

NS/27

NS/44

NS

0/3 (NS)

1/5 (NS)

1.43†

26.38†

0.05 (0.00–30.47)

Johnson, Uganda, 1993–NS (34)

Clinic or counseling attendees

6 mo INH 300 mg daily/placebo; partially double blind‡

931/787

Mean 2 y/1.6 y (PPD+/anergic); 16.1% vs. 30.6%

36/51 (70.6)

46/64 (71.9)

Growth on 0.1 μg/mL INH (BACTEC radiometric method) >1% growth on control medium

5/20 (56)

1/24 (52)

13.69

3.39

4.04 (0.50–32.80)

Rivero, Spain, 1994–2000 (35)

Clinic attendees; med. CD4 193/215

6 mo INH 300 mg daily/no treatment; not blind

82/77

24 mo; 26.8% vs. 7.8%

3/3 (100)

4/4 (100)

NS

3/3 (100)

4/4 (100)

36.59

51.95

0.70 (0.16–3.05)

Cohort study

Moreno, Spain, 1985–1994 (32)

Clinic attendees; med. CD4 689/648

9–12 mo INH (dose NS)/no treatment; not blind

29/92

89 mo vs. 60 mo; NS

3/3 (100)

39/43 (90.7)

Growth on 0.2 μg/mL INH >1% growth on control medium

2/2 (67)

0/12 (31)

118.64†

5.41†

21.95 (0.04–11,582.31)

*INH, isoniazid; TB, tuberculosis; RR, relative risk; CI, confidence interval; med., median; NS, not stated; Rx, treatment; VCT, voluntary counseling and testing; PPD, purified protein derivative.

†Calculated by adding 0.5 to numerator and denominator of both groups.

‡Unclear whether isoniazid and placebo group received the same number of tablets.