| Characteristic | HIV-positive (n = 127) | HIV-negative (n = 204) | p Value |
| Age, median (IQR) years | 45 (37–49) | 42 (36–48) | 0.222 |
| Education, undergraduate degree or more | 43.9% | 54.9% | 0.056 |
| Age at first anal intercourse, median (IQR) years | NA | 21 (18–26) | NA |
| Number of lifetime sexual partners | |||
| <50 | NA | 21.8% | NA |
| 51–500 | NA | 43.0% | NA |
| >500 | NA | 35.2% | NA |
| Number of male sex partners during the preceding 6 months, median (IQR) | 8 (2–30) | 10 (4–26) | 0.669 |
| Receptive anal intercourse during the preceding 6 months* | 69.9% | 66.3% | 0.505 |
| New casual sexual partner in previous 6 months | 77.2% | 74.1% | 0.528 |
| Condom use during the preceding 6 months, always | 27.6% | 22.3% | 0.279 |
| Current smoker | 40.6% | 23.3% | 0.001 |
| Injecting drug use, ever | 14.8% | 12.4% | 0.555 |
| Anal symptoms during the preceding 12 months | 54.1% | 48.4% | 0.328 |
| Anogenital sexually transmitted infection† | 25.4% | 13.0% | 0.006 |
| Most recent (within 3 months) CD4 count ⩾350 cells ×106/l | 76.5% | – | NA |
| HAART use during the preceding 6 months | 74.4% | – | NA |
*Any, whether protected or unprotected.
†Anal gonorrhoea, anal chlamydia or anal warts reported or diagnosed in the last 12 months.
HAART, highly active antiretroviral therapy; IQR, interquartile range; NA, not available.