Table 3.
Demographic and clinical predictors of drug substitutions in the first two years on second-line ART.
| Crude associations |
Adjusted associations, aHR (95% CI) |
|||||||
|---|---|---|---|---|---|---|---|---|
| Person-time | Failures, n (%) |
Incidence rate/100PY (95% CI) |
HR (95% CI) | Total sample | Stratified by initial second-line regimen |
|||
| AZT + ddI + LPVr | AZT/ABC + 3TC + LPVr | TDF + 3TC/FTC + LPVr | ||||||
| Year of second-line ART initiation | ||||||||
| 2004 to 2008 | 684.3 | 61 (12.5) | 8.9 (6.9–11.5) | 1 | 1 | 1 | 1 | 1 |
| 2009 to 2010 | 915.7 | 165 (22.7) | 18.0 (15.5–21.0) | 2.0 (1.5–2.7) | 3.6 (2.6–4.9) | 5.1 (3.4–7.1) | 1.2 (0.5–2.8) | 0.9 (0.3–2.5) |
| 2011 to 2013 | 2490.7 | 127 (7.0) | 5.1 (4.3–6.1) | 0.6 (0.4–0.8) | 2.6 (1.7–4.1) | 5.7 (1.0–32.2) | 0.7 (0.3–1.6) | 1.0 (0.4–2.5) |
| Initial second-line regimen | ||||||||
| AZT + ddI + LPVr | 744.1 | 173 (28.0) | 23.2 (20.0–27.0) | 1 | 1 | |||
| AZT/ABC + 3TC + LPVr | 1528.8 | 72 (6.5) | 4.7 (3.7–5.9) | 0.2 (0.2–0.3) | 0.2 (0.1–0.4) | |||
| TDF + 3TC/FTC + LPVr | 1772.6 | 107 (8.4) | 6.0 (5.0–7.3) | 0.3 (0.2–0.3) | 0.2 (0.1–0.8) | |||
| ATVr regimen | 45.1 | 1 (3.6) | 2.2 (0.3–15.7) | 0.1 (0.01–0.7) | 0.1 (0.02–3.2) | |||
| Sex | ||||||||
| Female | 2673.8 | 237 (11.8) | 8.9 (7.8–10.1) | 1 | ||||
| Male | 1417.0 | 116 (11.4) | 8.2 (6.8–9.8) | 0.9 (0.7–1.1) | ||||
| Age at second-line ART initiation | ||||||||
| Under 25 | 262.6 | 25 (12.8) | 9.5 (6.4–14.1) | 1 | ||||
| 25 to 29.9 | 472.7 | 48 (12.3) | 10.2 (7.7–13.5) | 1.1 (0.7–1.7) | ||||
| 30 to 39.9 | 1853.4 | 144 (10.6) | 7.8 (6.6–9.1) | 0.8 (0.5–1.2) | ||||
| 40 to 49.9 | 1106.4 | 102 (12.9) | 9.2 (7.6–11.2) | 1.0 (0.6–1.5) | ||||
| ≥50 | 395.7 | 34 (11.6) | 8.6 (6.1–12.0) | 0.9 (0.5–1.5) | ||||
| VL failure on first-line ART | ||||||||
| Yes | 1756.2 | 145 (11.0) | 8.3 (7.0–9.7) | 0.9 (0.8–1.2) | ||||
| No | 2334.5 | 208 (12.1) | 8.9 (7.8–10.2) | 1 | ||||
| Possible ADR on-first-line ART | ||||||||
| Yes | 1940 | 183 (13.4) | 9.4 (8.2–10.9) | 1.2 (0.9–1.5) | ||||
| No | 2150.7 | 170 (10.2) | 7.9 (6.8–9.2) | 1 | ||||
| CD4 at second-line ART initiation | ||||||||
| 199.9 cells/µl or less | 1295.0 | 120 (11.9) | 9.3 (7.7–11.1) | 1 | 1 | 1 | 1 | 1 |
| 200 to 349.9 cells/µl | 996.7 | 103 (14.3) | 10.3 (8.5–12.5) | 1.1 (0.9–1.4) | 1.1 (0.9–1.5) | 1.0 (0.7–1.5) | 1.2 (0.6–2.5) | 1.1 (0.7–1.9) |
| 350 cells/µl or higher | 957.6 | 68 (10.4) | 7.1 (5.6–9.0) | 0.8 (0.6–1.0) | 1.0 (0.7–1.3) | 0.9 (0.6–1.4) | 1.0 (0.5–2.1) | 0.8 (0.4–1.4) |
| Not measured/missing | 841.5 | 62 (9.6) | 7.4 (5.7–9.5) | 0.8 (0.6–1.1) | 1.5 (1.1–2.2) | 1.1 (0.5–2.3) | 2.1 (1.1–4.1) | 1.4 (0.8–2.6) |
| BMI at second-line ART initiation | ||||||||
| Underweight | 316.7 | 37 (14.7) | 11.7 (8.5–16.1) | 1 | ||||
| Normal | 1789.2 | 161 (12.2) | 9.0 (7.7–10.5) | 0.8 (0.5–1.1) | ||||
| Overweight | 988.4 | 82 (11.3) | 8.3 (6.7–10.3) | 0.7 (0.5–1.0) | ||||
| Obese | 646.9 | 47 (9.9) | 7.3 (5.5–9.7) | 0.6 (0.4–1.0) | ||||
| Not measured/missing | 349.4 | 26 (10.2) | 7.4 (5.1–10.9) | 0.6 (0.4–1.0) | ||||
| Anaemia at second-line ART initiation | ||||||||
| Yes | 620.3 | 67 (13.1) | 10.8 (8.5–13.7) | 1.2 (0.9–1.6) | 1.3 (1.0–1.7) | 1.2 (0.8–1.7) | 2.5 (1.4–4.5) | 0.9 (0.5–1.6) |
| No | 2701.6 | 247 (12.9) | 9.1 (8.1–10.4) | 1 | 1 | 1 | 1 | 1 |
| Not measured/missing | 768.8 | 39 (6.6) | 5.1 (3.7–6.9) | 0.6 (0.4–0.8) | 0.8 (0.5–1.2) | 1.0 (0.3–3.1) | 1.5 (0.7–3.2) | 0.5 (0.3–0.9) |
| AST/ALT ratio at second-line ART initiation | ||||||||
| <1 | 353.9 | 51 (19.4) | 14.4 (11.0–19) | 1 | 1 | 1 | 1 | 1 |
| 1 to 1.9 | 1050.9 | 138 (17.3) | 13.1 (11.1–15.5) | 0.9 (0.7–1.3) | 0.9 (0.6–1.2) | 0.8 (0.5–1.1) | 1.7 (0.6–5.1) | 1.3 (0.6–2.9) |
| 2 or higher | 172.9 | 16 (10.8) | 9.3 (5.7–15.1) | 0.6 (0.4–1.1) | 0.7 (0.4–1.2) | 1.0 (0.5–1.9) | 0.7 (0.1–6.4) | 0.4 (0.1–1.9) |
| Not measured/missing | 2512.9 | 148 (8.1) | 5.9 (5.0–6.9) | 0.4 (0.3–0.6) | 0.7 (0.5–1.1) | 0.7 (0.4–1.2) | 1.3 (0.4–4.0) | 1.0 (0.5–2.0) |
| WHO at second-line ART initiation | ||||||||
| I or II | 2443.0 | 219 (12.3) | 9 (7.9–10.2) | 1 | ||||
| III or IV | 722.0 | 70 (12.8) | 9.7 (7.7–12.3) | 1.1 (0.8–1.4) | ||||
| Not measured/missing | 925.7 | 64 (9.2) | 6.9 (5.4–8.8) | 0.8 (0.6–1.0) | ||||
| VL failure in follow-up | ||||||||
| Yes | 351.2 | 29 (14.2) | 8.3 (5.7–11.9) | 1.0 (0.7–1.4) | ||||
| No | 3739.5 | 324 (11.5) | 8.7 (7.8–9.7) | 1 | ||||
| ≥3 months late for scheduled visit in follow-up | ||||||||
| Yes | 496.5 | 23 (7.7) | 4.6 (3.1–7.0) | 0.5 (0.3–0.8) | 0.4 (0.3–0.6) | 0.4 (0.2–0.7) | 0.5 (0.2–1.5) | 0.3 (0.1–0.8) |
| No | 3594.2 | 330 (12.1) | 9.2 (8.2–10.2) | 1 | 1 | 1 | 1 | 1 |
| Possible ADR in follow up | ||||||||
| Yes | 629.3 | 88 (21.1) | 14.0 (11.3–17.2) | 1.8 (1.4–2.3) | 1.6 (1.2–2.0) | 1.5 (1.1–2.1) | 1.9 (1.1–3.4) | 1.5 (0.9–2.5) |
| No | 3461.4 | 265 (10.2) | 7.7 (6.8–8.6) | 1 | 1 | 1 | 1 | 1 |
| Clinic type | ||||||||
| HIV clinic in hospital complex | 2136.5 | 211 (13.4) | 9.9 (8.6–11.3) | 1 | 1 | 1 | 1 | 1 |
| Local CHC | 622.9 | 43 (9.4) | 6.9 (5.1–9.3) | 0.7 (0.5–1.0) | 0.9 (0.6–1.2) | 1.1 (0.7–1.9) | 0.7 (0.4–1.5) | 0.8 (0.5–1.5) |
| NGO clinic | 1331.3 | 99 (10.0) | 7.4 (6.1–9.1) | 0.8 (0.6–1.0) | 0.9 (0.7–1.1) | 0.8 (0.5–1.2) | 0.6 (0.3–1.2) | 1.1 (0.7–1.7) |