Table 1.
Summary of the Adjusted Least Squares Regression for the Full Data Set
| All patients |
Patients infected ≤8 years |
|||
| Measure | No. (%) of patients | Median (95% CI) | No. (%) of patients | Coefficient (95% CI) |
| Total no. of patients | 3,307 (100) | – | 2,729 (100) | – |
| Time since infection (per year) | – | .195 (.170–.221)a | – | .158 (.141–.175)a |
| Time since infection (quadratic term) | – | −.007 (−.008 to −.005)a | – | NA |
| Female sex | 714 (21.6) | .034 (−.053 to .121) | 542 (19.9) | .054 (−.047 to .159) |
| Age by quartile, years | ||||
| 25–30 | 949 (28.7) | Referent | 862 (31.6) | Referent |
| 33–35 | 789 (23.9) | .146 (.060–.233)a | 605 (22.2) | .140 (.047–.233)a |
| 38–41 | 781 (23.6) | .232 (.144–.319)a | 613 (22.5) | .247 (.145–.338)a |
| 45–54 | 788 (23.8) | .237 (.146–.328)a | 649 (23.8) | .252 (.153–.348)a |
| Ethnicity | ||||
| White | 2,933 (88.7) | Referent | 2,455 (90.0) | Referent |
| Black | 63 (1.9) | .169 (−.060 to .399) | 58 (2.1) | .080 (−.122 to .290) |
| Hispano-American | 97 (2.9) | .325 (.141–.509)a | 89 (3.3) | .343 (.140–.546)a |
| Asian | 57 (1.7) | .090 (−.147 to .328) | 55 (2.0) | .095 (−.109 to .290) |
| Unknown ethnicity | 157 (4.7) | −.039 (−.200 to .122) | 72 (2.6) | .001 (−.186 to .211) |
| Mode of HIV acquisition | ||||
| Heterosexual risks | 857 (25.9) | Referent | 722 (26.5) | Referent |
| Intravenous drug use | 862 (26.1) | .233 (.142–.323)a | 595 (21.8) | .247 (.140–.357)a |
| Homosexual risks | 1,482 (44.8) | −.066 (−.154 to .021) | 1326 (48.6) | −.063 (−.154 to .031) |
| Unknown risk | 106 (3.2) | .121 (−.062 to .305) | 86 (3.2) | .186 (−.006 to .416) |
| Laboratory | ||||
| Laboratory A | 213 (6.4) | Referent | 178 (6.5) | Referent |
| Laboratory B | 1,450 (43.8) | .407 (.274–.540)a | 1176 (43.1) | .357 (.246–.456)a |
| Laboratory C | 319 (9.6) | .404 (.247–.562)a | 264 (9.7) | .312 (.180–.430)a |
| Laboratory D | 1,325 (40.1) | .787 (.653–.921)a | 1111 (40.7) | .705 (.594–.803)a |
| Calendar year of sequencing, median (IQR) | 2007 (2006–2008) | .119 (.101–.137)a | 2007 (2006–2008) | .111 (.093–.127)a |
| HIV RNA load at time of GRT by 33 percentiles, log10 copies/mL | ||||
| 3.3–4.0 | 1,013 (30.6) | Referent | 829 (30.4) | Referent |
| 4.5–4.8 | 1,013 (30.6) | .097 (.017–.176)a | 859 (31.5) | .043 (−.050 to .128) |
| 5.2–5.7 | 1,011 (30.6) | .136 (.056–.217)a | 853 (31.3) | .063 (−.020 to .151) |
| HIV RNA load missing | 270 (8.2) | −.106 (−.235 to .023) | 188 (6.9) | −.130 (−.273 to .026) |
| Constant term (1 unit = 1%) | – | −1.046 (−1.231 to −.860) | – | −.885 (−1.042 to −.732) |
NOTE. The 95% confidence intervals (CIs) were estimated with bootstrapping over 1,000 replicates. Note that for the quadratic model (all patients) both the linear and the quadratic term significantly improve the fit, but not when only the first 8 years of infection were considered. GRT, genotypic resistance test; HIV, human immunodeficiency virus; IQR, interquartile range; NA, not applicable.
a
Statistically significant by the Wald test.