Table 2. Bivariable associations between covariates and outcomes, stratified by the period of combination antiretroviral therapy initiation (2000–2006 and 2007–2012) and CD4+ cell count level at combination antiretroviral therapy initiation.
| (a) Using the CD4+ cell count cut-off of 500 cells/ml at cART initiation | |||||
|---|---|---|---|---|---|
| Covariate | Period (years) and CD4+ cell count (cells/μl) | P | |||
|
| |||||
| 2000–2006 and <500 | 2000–2006 and ≥500 | 2007–2012 and <500 | 2007–2012 and ≥500 | ||
| Sex, n (%) | |||||
| Male | 1309 (80%) | 38 (76%) | 1683 (80%) | 298 (87%) | 0.0073 |
| Female | 319 (20%) | 12 (24%) | 418 (20%) | 43 (13%) | |
| Age (years), median (Q1–Q3) | 42 (36–48) | 39 (33–45) | 42 (35–49) | 39 (32–47) | <0.0001 |
| Viral load (log10 copies/ml) at cART initiation, median (Q1–Q3) | 5.00 (4.69–5.00) | 4.88 (4.32–5.00) | 4.80 (4.27–5.00) | 4.46 (4.02–5.00) | <0.0001 |
| History of injection drug use, n (%) | |||||
| No | 710 (44%) | 25 (50%) | 948 (45%) | 156 (46%) | <0.0001 |
| Yes | 674 (41%) | 16 (32%) | 735 (35%) | 76 (22%) | |
| Unknown | 244 (15%) | 9 (18%) | 418 (20%) | 109 (32%) | |
| Follow-up (months), median (Q1–Q3) | 104 (84–129) | 103 (77–127) | 47 (29–65) | 30 (20–42) | <0.0001 |
| Adherence to therapy during the first 6 months on cART, n (%) | |||||
| ≥95% | 1241 (76%) | 29 (58%) | 1670 (80%) | 279 (82%) | <0.0001 |
| 80 to <95% | 74 (5%) | 6 (12%) | 111 (5%) | 22 (6%) | |
| 40 to <80% | 195 (12%) | 10 (20%) | 223 (11%) | 27 (8%) | |
| 0 to <40% | 118 (7%) | 5 (10%) | 97 (5%) | 13 (4%) | |
| Suppression at 9 months, n (%) | |||||
| Yes | 1075 (66%) | 31 (62%) | 1531 (73%) | 289 (85%) | <0.0001 |
| No | 553 (34%) | 19 (38%) | 570 (27%) | 52 (15%) | |
| Drug resistance at cART initiation, n (%) | |||||
| No | 1581 (97%) | 46 (92%) | 2047 (97%) | 334 (98%) | 0.1321 |
| Yes | 47 (3%) | 4 (8%) | 54 (3%) | 7 (2%) | |
| Developing resistance to any class during follow-up, n (%)a | |||||
| No | 1278 (81%) | 42 (91%) | 1913 (94%) | 327 (98%) | <0.0001 |
| Yes | 303 (19%) | 4 (9%) | 134 (6%) | 7 (2%) | |
| Developing an AIDS-defining illness during follow-up, n (%) | |||||
| No | 1432 (88%) | 48 (96%) | 1998 (95%) | 337 (99%) | <0.0001 |
| Yes | 196 (12%) | 2 (4%) | 103 (5%) | 4 (1%) | |
| Status at the end of follow-up, n (%) | |||||
| Alive | 982 (60%) | 26 (52%) | 1618 (77%) | 267 (78%) | <0.0001 |
| Death | 339 (21%) | 11 (22%) | 135 (6%) | 7 (2%) | |
| Loss to follow-up | 307 (19%) | 13 (26%) | 348 (17%) | 67 (20%) | |
| Overall | 1628 (40%) | 50 (1%) | 2101 (51%) | 341 (8%) | |
|
| |||||
| (b) Using the CD4+ cell cut-off 350 cells/μl at cART initiation | |||||
| Period (years) and CD4+ cell count (cells/ml) | |||||
|
|
|||||
| Covariate | 2000–2006 and <350 | 2000–2006 and ≥350 | 2007–2012 and <350 | 2007–2012 and ≥350 | P |
|
| |||||
| Sex, n (%) | |||||
| Male | 1221 (80%) | 126 (78%) | 1292 (80%) | 689 (84%) | 0.0436 |
| Female | 295 (20%) | 36 (22%) | 330 (20%) | 131 (16%) | |
| Age (years), median (Q1–Q3) | 42 (36–48) | 41 (33–48) | 43 (35–50) | 41 (32–47) | <0.0001 |
| Viral load (log10 copies/ml) at cART initiation, median (Q1–Q3) | 5.00 (4.72–5.00) | 4.85 (4.20–5.00) | 4.88 (4.36–5.00) | 4.48 (3.98–4.96) | <0.0001 |
| History of injection drug use, n (%) | |||||
| No | 658 (43%) | 77 (48%) | 721 (44%) | 383 (47%) | <0.0001 |
| Yes | 633 (42%) | 57 (35%) | 613 (38%) | 198 (24%) | |
| Unknown | 225 (15%) | 28 (17%) | 288 (18%) | 239 (29%) | |
| Follow-up (months), median (Q1–Q3) | 104 (84–128) | 109 (86–140) | 51 (33–67) | 33 (22–49) | <0.0001 |
| Adherence to therapy during the first 6 months on cART, n (%) | |||||
| ≥95% | 1157 (76%) | 113 (70%) | 1294 (80%) | 655 (80%) | <0.0001 |
| 80 to <95% | 70 (5%) | 10 (6%) | 79 (5%) | 54 (7%) | |
| 40 to <80% | 183 (12%) | 22 (14%) | 173 (11%) | 77 (9%) | |
| 0 to <40% | 106 (7%) | 17 (10%) | 76 (4%) | 34 (4%) | |
| Suppression at 9 months, n (%) | |||||
| Yes | 1000 (66%) | 106 (65%) | 1138 (70%) | 682 (83%) | <0.0001 |
| No | 516 (34%) | 56 (35%) | 484 (30%) | 138 (17%) | |
| Drug resistance at cART initiation, n (%) | |||||
| No | 1472 (97%) | 155 (96%) | 1578 (97%) | 803 (98%) | 0.3560 |
| Yes | 44 (3%) | 7 (4%) | 44 (3%) | 17 (2%) | |
| Developing resistance to any class during follow-up, n (%)a | |||||
| No | 1178 (80%) | 142 (92%) | 1457 (92%) | 783 (98%) | <0.0001 |
| Yes | 294 (20%) | 13 (8%) | 121 (8%) | 20 (2%) | |
| Developing an AIDS-defining illness during follow-up, n (%) | |||||
| No | 1329 (88%) | 151 (93%) | 1523 (94%) | 812 (99%) | <0.0001 |
| Yes | 187 (12%) | 11 (7%) | 99 (6%) | 8 (1%) | |
| Status at the end of follow-up, n (%) | |||||
| Alive | 916 (60%) | 92 (57%) | 1245 (77%) | 640 (78%) | <0.0001 |
| Death | 316 (21%) | 34 (21%) | 119 (7%) | 23 (3%) | |
| Loss to follow-up | 284 (19%) | 36 (22%) | 258 (16%) | 157 (19%) | |
| Overall | 1516 (37%) | 162 (4%) | 1622 (39%) | 820 (20%) | |
Q1: 25th percentile, Q3: 75th percentile.
a
Denominator is the number of patients without baseline resistance. P values should be used to compare across categories of our main exposure. Number in parenthesis for n (%) refers to column percentages.