Prevalence of HIV infection according to sample characteristics
| Variable | n (%) | HIV infections | HIV prevalence % (95% CI) |
| Total | 3687 (100) | 12 | 0.35 (0.13 to 0.57) |
| Sex | |||
| Male | 1718 (47) | 8 | 0.51 (0.12 to 0.89) |
| Female | 1969 (53) | 4 | 0.20 (0.00 to 0.44) |
| Country of origin | |||
| Spain | 2749 (75) | 8 | 0.30 (0.06 to 0.53) |
| Other | 938 (25) | 4 | 0.61 (0.03 to 1.18) |
| Age | |||
| 16–20 | 744 (20) | 0 | – |
| 21–30 | 827 (22) | 5 | 0.65 (0.01 to 1.29) |
| 31–40 | 765 (21) | 5 | 0.71 (0.02 to 1.41) |
| 41–60 | 743 (20) | 1 | 0.11 (0.00 to 0.40) |
| ≥60 | 608 (17) | 1 | 0.15 (0.00 to 0.51) |
| Social class* | |||
| I and II | 890 (25) | 3 | 0.29 (0.00 to 0.71) |
| III | 876 (24) | 2 | 0.23 (0.00 to 0.60) |
| IVa | 938 (26) | 5 | 0.61 (0.11 to 1.18) |
| IVb and V | 884 (25) | 1 | 0.16 (0.00 to 0.47) |
| Educational level | |||
| Primary | 580 (16) | 2 | 0.38 (0.00 to 0.96) |
| Lower secondary | 1205 (33) | 4 | 0.41 (0.00 to 0.86) |
| Upper secondary | 1022 (28) | 4 | 0.39 (0.00 to 0.83) |
| University | 833 (23) | 2 | 0.24 (0.00 to 0.63) |
↵* Social class was assigned based on occupation into 5 groups (I–V) with I having the highest social class.