Table 1. Baseline characteristics of study participants.
| Characteristics | SDPIC | Others | Total | |
| Male, n = 630, n (%) | 462 (96.7) | 143 (94.1) | 605 (96.0) | |
| Age, n = 611, median (range) | 33 (16–67) | 35 (18–58) | 33 (16–67) | |
| Race/Ethnicity, n = 463 | Non-Hispanic white, n (%) | 155 (48.1) | 63 (44.7) | 218 (47.1) |
| Non-Hispanic black, n (%) | 14 (4.4) | 22 (15.6) | 36 (7.8) | |
| Hispanic, n (%) | 122 (37.9) | 42 (29.8) | 164 (35.4) | |
| Other, n (%) | 31 (9.6) | 14 (9.9) | 45 (9.7) | |
| Risk Factors for HIV | MSM, n = 590, n (%) | 444 (97.2) | 125 (94.0) | 569 (96.4) |
| Heterosexual, n = 614, n (%) | 29 (6.1) | 16 (11.4) | 45 (7.3) | |
| Injection drug use, n = 623, n (%) | 17 (3.6) | 12 (8.3) | 29 (4.7) | |
| Elapsed time | Days from HIV-1 infection to study entry, n = 478, median (range) | 70 (7–170) | N/A* | N/A* |
| Days from study entry to first pol sequence, n = 640, median (range) | 0 (0–1462) | 0 (0–1813) | 0 (0–1813) | |
| Days from study entry to start or ART, n = 341, median (range) | 72 (0–3718) | N/A* | N/A* | |
| Weeks from study entry to last visit, n = 634, median (range) | 98.3 (0–667.7) | 2.0 (0–293.2) | 60.1 (0–667.7) | |
| Laboratories (n = 616) | CD4 (cells/mm3), median (range) | 500 (67–1380) | 378 (7–2273) | 484 (7–2273) |
| Viral load (HIV–1 RNA log10 copies/mL), median (range) | 5.0 (0–7.8) | 4.1 (0–7.0) | 4.9 (0–7.8) | |
| 50–1500 copies/mL, n (%) | 27 (5.7) | 38 (27.5) | 65 (10.6) | |
| 1501–,000 copies/mL, n (%) | 63 (13.2) | 24 (17.4) | 87 (14.1) | |
| 10,001–100,000 copies/mL, n (%) | 143 (29.9) | 46 (33.3) | 189 (30.7) | |
| >100,000 copies/mL, n (%) | 245 (51.3) | 30 (21.7) | 275 (44.6) | |
SDPIC = San Diego Primary Infection Cohort, Others = non-SDPIC participants, MSM = men who have sex with men, ART = antiretroviral therapy.
*Date of infection and start of ART were not estimated for non-SDPIC participants.