Table 5 Factors associated with rates of combination antiretroviral treatment changes

N

# events

Rate/follow-up year

RR (95% CI)

Overall

1846

1491

0.29

Age(per 10 years)

1.04 (0.98 – 1.12)

Sex

   Male

1324

1081

0.29

1.00

   Female

520

408

0.29

1.01 (0.87 – 1.17)

Exposure

   Heterosexual

1333

1052

0.28

1.00

   IDU + others + unknown

192

171

0.40

1.43 (1.16 – 1.78)

   Homosexual

321

268

0.29

1.09 (0.91 – 1.30)

Income category

   Low income

451

263

0.24

1.00

   Lower middle income

859

669

0.29

1.14 (0.95 – 1.36)

   Upper middle high income

536

559

0.35

1.31 (1.09 – 1.58)

Previous AIDS

   No

1363

1331

0.29

1.00

   Yes

483

160

0.29

1.09 (0.94 – 1.27)

CD4

   < 50

432

335

0.29

1.00

   51 – 100

213

145

0.27

0.93 (0.72 – 1.20)

   101 – 200

309

224

0.27

0.98 (0.79 – 1.22)

   - > 200

232

221

0.30

1.14 (0.90 – 1.28)

   Missing

660

566

0.30

HIV-RNA

   ≤ 100,000

210

261

0.37

1.00

   > 100,000

256

234

0.31

0.84 (0.66 – 1.07)

   Missing

1380

996

0.27

Drug class combination

   d4T/3TC/NVP

676

219

0.15

1.00

   with NNRTI, no PI

791

576

0.24

1.59 (1.35 – 1.88)

   with PI, no NNRTI

344

390

0.42

2.88 (2.40 – 3.45)

   NRTI only

17

72

0.71

5.38 (3.94 – 7.35)

   Others

18

234

1.14

Combination ³

   First

1846

764

0.23

1.00

   Second

719

376

0.41

1.22 (1.03 – 1.44)

   Third +

692

351

0.41

0.72 (0.58 – 0.89)

Calendar year

   ≥ 2003

808

1053

0.27

1.00

   ≤ 1999 – 2002

1038

438

0.36

1.23 (1.10 – 1.40)

Number of drugs available ⁴

   > 12

922

739

0.27

1.00

   ≤ 12

924

752

0.32

1.19 (1.04 – 1.36)